MINI MIDI LESSONS 12Aug89-MGM #1a INTRODUCTION Almost everyone has a natural curiosity about MIDI, whether or not there are serious intentions of using it. In this series of mini lessons on MIDI, I will attempt to answer some of the more common questions about it. We will discuss - What is MIDI ? What do I need for MIDI ? Do I need to know music to use MIDI ? What is a sequencer ? What are the differences in keyboards ? What does MIDI cost ? Why should I do MIDI ? It is almost impossible to discuss music or MIDI without using some of the technical terms of the trade. In this series of studies we will try to say everything in such a way that anyone can understand it. A glossary will be presented to help with the words which may remain in doubt. Most of the lessons of this series will be presented on a single page. The first lesson, "What is MIDI ?", will finish this page and continue on the next. - Morris G. Miller WHAT IS MIDI ? MIDI is an acronym for "Musical Instrument Digital Interface". It is a defined means for interconnecting musical instruments and other related equipment for the reproduction of music. It now includes your computer and the programs for MIDI, keyboards, syn- thesizers and samplers, sequencers, recorders, editors, librarians, scorers, and a host of other equipment and functions. MIDI is the electrical and physical specifications for these in- terconnections. It forms the "standards". The MIDI standards define the hardware connections and wiring to connect and send signals between the instruments, such that one can control or inform the other of musical events. The send wire of one connects to the receive of the other, and visa-versa. Signals are sent in serial, much like the serial printer or modem connection on your computer; one wire to send, one wire to receive. On some computers the MIDI interface plugs into the serial modem port of the computer. On others the MIDI port is built in as a separate interface. 1 MINI MIDI LESSONS 12Aug89-MGM #1b WHAT IS MIDI ? The serial pulses sent between instruments are organized into 8-bit codes. The MIDI standard defines the meanings of these codes so that all instruments speak the same code language. Not all the instruments respond to all the codes defined, but those that respond to any one code all respond in the same manner. Electronically, MIDI also defines the current and voltage limits of the pulses and the bit rate for the pulses. In this there are now two standards, but any instrument designed for the faster standard, will respond properly to the original, slower, standard unless it specifically so states. Not to worry. For what you and I are doing, either of these are sufficient. The MIDI connections on your instruments are a 5-pin DIN. There are three kinds: MIDI IN - the instrument can receive MIDI code. MIDI OUT - the instrument can send MIDI code. MIDI THRU - the instrument can repeat to the next instrument what was received on MIDI IN. Not all instruments will have all three ports. This is a clue to how that instrument can fit into the MIDI hookup. The full definitions for midi codes are available from many sources and will not be repeated here. Codes are defined for turning each note on and off, the note attack (how hard the key is struck), touch pressure (how hard the key is held down), release (how quickly the key is released), patch changes (selecting the voice to play), pedal control (sustain, soft, etc.), glissando and portamento (glide between notes), modulation (vibrato or tremolo), and others. Codes are also defined for the individual manufacturers, called exclusive codes. This allows each manufacturer to have special codes for the control of functions on a keyboard that is dif- ferent from all other keyboards. It is this "feature" that will prompt you to make some decisions about the type of keyboard to use and the programs to buy before sinking a lot of money into it. The two must work together. Note that MIDI does NOT SEND THE SOUND of the notes played. MIDI sends signals to indicate what the PERFORMER DID. MIDI sends codes to indicate which key(s) was pressed, when it was pressed, when it was released, which control was operated and how much it was operated. When played back from the computer the keys are pressed again exactly the same as before, and the same controls are operated again exactly the same way. Reminiscent of a player piano, no ? Only it doesn't have to be a piano. It might be two horns and a banjo. That's neeeet ! Morris G. Miller 2 MINI MIDI LESSONS 12Aug89-MGM #2 WHAT DO I NEED FOR MIDI ? Coming from a computer user this question relates to "what do I need to add in order to use MIDI?" Selecting your computer is another subject, but there are MIDI connections for almost every computer now made. As a matter of fact, many MIDI instruments can be used without a "computer" and have their own computer functions built into them. Many keyboards can record and play back the songs played on them. For your computer to send a song to the keyboard you will need a sequencer or player program. There are some simple player programs and a few decent sequencers and editors available in the public domain. Commercially available programs are much better, but you pay for what you get. Another lesson will go into more detail about sequencers and editors. Basically, the sequencer will allow you to record a song as you play it, edit mistakes and make musical performance changes, select the voices, and play the song back to the synthesizer. Some computers have plug in card slots. MIDI interface cards are available for MAC, IBM-PC, Apple, and others. Synthesizer cards are available for MAC and IBM-PC. If your computer does not have a MIDI interface built in, Apple makes a simple interface to plug into a serial port, but programs to drive it may be a problem. Synthesizers can be purchased without keyboards. All keyboards have synthesizers in them. It is the keyboard which sends the performance signals to the computer for recording. When played back from the computer it is the synthesizer which makes the voice sounds you hear. You can play any song to a synthesizer whether it has a keyboard or not. Therefore there are two fac- tors involved: (a) If you know you will seldom be entering notes or play- ing the keyboard, buy a keyboard looking for the best synthesizer. You'll save enough money on the cheaper keyboard to buy another synthesizer without a keyboard. (b) Otherwise buy the best keyboard you can, with less regard to the quality of synthesizer it contains. Get a better synthesizer as a separate item. You will need an amplifier and speaker system. Any good home music system will be great. Add to it an audio mixer for combin- ing the sound output of two to four separate synthesizers and microphone inputs. Radio Shack has a reasonably good one at a modest price. If your music system has a cassette recorder in it then all the better. Record your performances and take it with you. You don't have to buy everything at once. When an item is to become permanent to the system, then buy the best you think you can afford. Morris G. Miller 3 MINI MIDI LESSONS 12Aug89-MGM #3 DO I NEED TO KNOW MUSIC TO USE MIDI ? Yes. And no. There's nothing like a definitive answer, but the proper answer depends on what you want to do with your MIDI system. It re- quires no knowledge of music to play pre-recorded songs. You can change the voices, tempo, attack (volume) and many other com- ponents of musical character and style having no knowledge of music. You can have someone else play a song while you record it and have no knowledge of music. You can even do a lot of editing to a song with no knowledge of music. But, it does help. If you have no knowledge of music, you will be pleasantly surprised how quickly you can learn what you need to know of the rudiments of music once you start entering a new song into the editor. Keep in mind that it is not necessary to "play" a song to enter it into the editor. There are at least a half dozen different ways to get music into the sequencer. Some easier than others, but others more suitable to the circumstances than some ! We are not talking about "composing" music or knowing all about chords and patterns. It will be necessary to learn the relative tonal positions of lines and spaces on the musical staffs. It will be necessary to learn what note shape has to do with time and duration. It will be necessary to recognize the markings in the time and key signature of a score. All this should take about an hour of talking to your daughter, who has been taking those expensive piano lessons, and the next three days to enter your first two simple songs. After that it's all down hill. Pre-recorded songs can give hours (literally) of great pleasure by the nominal process of examining them in the edit buffer of the sequencer and finding for yourself what the affects are. Have that daughter play the song while you record it - mistakes matter not. Play with the editor until all notes are like the score. This will quickly let you see for yourself how the notes correspond to position on the staff, how shape relates to dura- tion, and how the signature affects the individual note pitch, and how quickly 10pm can arrive. Assign voices, adjust tempo, set the MIDI channel, set up the synth patches and presto ! New song. Yes, you will need to know some "music". You do not need to know music theory. What you need to know at a minimum, you can learn very quickly by doing. Just don't burst out singing too loud! Happy MIDI. Morris G. Miller 4 MINI MIDI LESSONS 12Aug89-MGM #4 WHAT IS A SEQUENCER ? The sequencer really is the very heart of a MIDI system. It is the sequencer in which you can record, edit, arrange performances and play back your music to the synthesizers. In this context the sequencer includes all the accessory programs which work together to make the total MIDI package. Some program vendors have every- thing rolled into one program while others provide a number of separate programs which work together. It is the number of refined features and various added functions that makes one sequencer different from another. You will like the display and the way things are done with one and not in another. I probably prefer mine just the other way around. This is why you should see a few total packages working before you in- vest. A public domain program will keep you going until it is time to commit and make the plunge. When you do commit, make sure it is a package that offers support for the synthesizers you will be using. Here are the major things MIDI control programs do: 1. Record a song played on the keyboard. Enter real time (as played) or step (one note at a time). 2. Provide a minimum of 8 song tracks. Some have up to 60 or more tracks. Each track holds a separate song or part of a song. 3. Editing notes, duration, attack, release, portamento, etc. Edit notes into tracks. 4. Copy and move song sections into other positions. Loop song sections (repeats). 5. Set synthesizer patch selections into song. Change patch, tempo and other parameters in song performance. 6. Convert a song into a score sheet and print. Print MIDI parameters of song performance. 7. Perform multiple song files in named sequence, like songs of an album. 8. Create and edit new voices for the synthesizers. Dump the synthesizer voice parameters and store on disk. Restore again on demand. Talk to the people who use synthesizers and try as many of them as possible. Make your selection carefully and plan to acquire as many of the function modules as you can afford. You do not have to have them all at once. Morris G. Miller 5 MINI MIDI LESSONS 12Aug89-MGM #5 WHAT ARE THE DIFFERENCES IN KEYBOARDS ? Keyboards for MIDI have two main functions - to play music and to control the instruments making the sounds. Not all keyboards have the same number of playing keys. Nor keys of the same size. My fat fingers will not play a reduced size keyboard. A song may be entered with a keyboard of 3 octaves and then edited (and played) over a full 8 octaves. It just takes more editing. I prefer a 5-octave keyboard, but it is mainly a personal preference and dollar investment. The MIDI keyboard is more than just keys to play on. With MIDI a number of sound instruments (synthesizers, samplers, drum and rhythm machines, and program sequencers) may be controlled by an operator console. The keyboard is often that console, especially in a live performance. The console controls may be recorded as they are performed. When re-played by the sequencer, it replaces the original performer, sending all the original, or edited, per- formance controls. The main difference between keyboards, then, is in how many of the MIDI control signals it sends to the sequencer in perfor- mance. How many of these controls you need depends on how much of a performer you are - and how much of the control you do not mind entering by the editor. Take the action of pressing a note key, for example. Full touch sensitivity means that MIDI information is sent saying (a) which note was pressed and when it was pressed; (b) how quickly the key was pressed (attack velocity - often used for loudness control); (c) how hard the key is pressed after it is down (after touch pressure - sometimes used for vibrato control); (d) which note is released and when it is released; (e) how quickly the key was released (release velocity - sometimes used for portamento or glissando). All keyboards having MIDI will send the basic note on/off infor- mation of (a) and (d). Some will send (b) and maybe (c) informa- tion. Few, except the most expensive, will send it all. Not all synthesizers (in a keyboard or otherwise) are stereo. Many are mono only. Not all keyboards include the accessory con- trols of pitch bend (note glide), foot switches (on/off functions), foot pedals (variable control for soft-loud, etc.), or pan (stereo balance). As a side effect, if a keyboard does not generate a MIDI func- tion, then very likely the embedded synthesizer will not respond to that control either. Without touch velocity the loudness is not controlled. Try the instrument to see what it will or will not do. Morris G. Miller 6 MINI MIDI LESSONS 12Aug89-MGM #6 WHAT DOES MIDI COST ? Like watches, MIDI can cost as little or as much as you want to put into it. I can give you some price ranges, but they are ar- bitrary. I can give you some recommendations, but they are generalities. You will still have to evaluate for your applica- tion and make the final decisions. The three basic components, aside from the computer, are the se- quencer (software), keyboard and synthesizers, and the music sound system. The first two are most urgent to this discussion. A starter sequencer is available from the public domain for most popular computers. I recommend starting with one, even though I did not. This allows you to find and settle on a keyboard first. Most vendors provide low-end versions of their sequencers start- ing in the $30 to $60 range. The high-end versions of the same programs will be from $300 to $700. Accessories can cost up to an additional $500, costing $20 to $100 for each added utility. Software is expensive, but good programs are worth it. The low- end versions will not have all the features of the expensive ver- sions, naturally, but will possibly have everything you need or want. Again, try them first. Keyboard selection is more difficult, and should come first. As in a previous discussion, decide whether you need your emphasis on the keyboard or the synthesizer. Don't be carried away by the "local" features, such as rhythms, chords and fancy noises the keyboard can make while you play it. Most of these things will not be recorded on the MIDI. However, if your daughter will en- joy playing it live, then consider it. New keyboards start about $130 and go to $3000 or more. Keep an eye on swap meets, yard sales, classified adds and pawn shops. Someone gets a good bar- gain every day, somewhere. Not all keyboards give the same amount of information. If touch sensitivity (how fast and hard the key is pressed and released) is important, then keep it in mind. The difference ? If the keyboard does not record how loud the note is performed, then it must be added in the editor. If the keyboard does not respond to touch sensitivity, it is very probable the synthesizer in it also does not. That could be more important. Does it have input for foot pedals, modulation control, pitch bend (glide pitch while playing), or pan (stereo balance). Many keyboards and their syn- thesizers are only monophonic (one output, not stereo). Examine it carefully. Seek advice and help if necessary. You can add the sound system and cassette recorder as anything from a simple AM/FM radio and cassette recorder to a grand home music system. It should be stereo. The rest I leave to your im- agination. Morris G. Miller 7 MINI MIDI LESSONS 12Aug89-MGM #7 WHY SHOULD I DO MIDI ? Maybe I shouldn't. MIDI is not for everyone any more than is rhubarb pie. Ugh ! Why would I want to hear Fredrick Chopin's Polonaise played on a synthesizer when I have a compact disk of Philippe Entremont in performance ? Because 1) I had fun entering the music; 2) I gained a lot of understanding of both the music and Chopin by doing so; 3) it was edited until I had the performance inter- pretation I felt Chopin himself would give it; 4) I feel it is MY performance - as though I am playing it - doing it MY way; 4) It can be performed on any of a dozen and a half different pianos - my choice; 5) or played by a trumpet and bass; 6) or whatever in- terpretation I want to put on it. Besides, who says I have to play Chopin ? Try your hand at Moonstruck. I'll bet you don't have that on CD. Put your own weird interpretations of sounds into it. It can sound "spaced out", tin-pan, heavy-metal, or whatever. Or, very smooth. Did you ever want to sing with your own orchestra or combo ? You got it ! Record it and amaze your friends. It's a great way to find out just who your friends really are. And, who is not ! Sheet music is in abundance. A lot of it is not on CD. Some of it was out of production before the record player was invented. You have a way of playing it anyway. And talk about inventing - that is my main interest in MIDI. I write songs, mostly a cappella (vocal). I try my songs on MIDI with instruments having the range of voices which will do the final performance. I can hear my songs without having to sing and record all the parts myself (which I often do). MIDI allows me to edit until I have my song just the way I want it. The sequencer I use also has tape sync and SEMPTE (another subject). I have an an 8-channel recorder which allows me to record eight times with all recordings in sync - playing to the same conductor, if you please. I record the strings on one track, the wood winds on another, the brass, percussion, reeds and bass on other tracks. When I play it back the entire or- chestra plays. This is accomplished with two synthesizers, play- ing no more than six to eight instruments at a time. Maybe you should not do MIDI. But, if you like to have fun with music, there is no other way you can have this much fun with a full orchestra from the confines of your own music room at home. So, do it ! Morris G. Miller 8 MINI MIDI LESSONS 12Aug89-MGM #8 WHAT IS A SYNTHESIZER ? A sine wave tone at any frequency is the most pure and undis- torted sound we can make; it is much like a bird whistle, when given notes to play. Most instruments have some pure note characteristics. Only some. There is no musical instrument pleasing to the ear which produces sound in the purity of a sine wave. It is the characteristic distortions of an instrument that makes it sound like that instrument and none other. The trick, then, is to electronically produce sound with the proper distortion and harmonic characteristics in order to sound like some instrument we know and love. Or, for that matter, once we learn to create the sounds of instruments found naturally, and understand the natural laws which govern those sounds, we can create by those rules of nature new sounds of instruments not yet devised by craftsmen. Ain't that exciting ? The English prefixes "syn" and "sym" mean, simply, "together". The word "synthesis" is from the old Greek, meaning "to put together". One way to create distortion in sounds, otherwise pure, is to put two or more of them together with varying amplitudes and phase relationships - and you have the beginnings of a violin, guitar, or piano sound. Add to that control over the amplitude envelopes and it can be quite good. To give even greater flexibility to the sound synthesis, each tone to be combined (operators) can be given a distortion. The easiest way to do this is to generate the tone in various wave forms (shapes). The most common such wave forms are sine wave (no distortion), square wave (rich in odd numbered harmonics), triangle or peaked wave (weak low-order odd harmonics), sawtooth (rich in both odd and even harmonics), and pulse shapes (harmonic content variable). By mixing the selected operators to various degree, many different sounds can be produced. To take this process one step further, allow a low frequency operator (LFO), of one of these shapes, to determine the amplitude or frequency modulation of another (the carrier) at the desired note frequency. Add feedback so that the modulator can modulate itself to some degree. Now combine mixes of these sig- nals in various combinations and you have the synthesizers avail- able today. To make a new voice, select the manner in which you want the modulators, carriers and feedback loops to be interconnected (the algorithm). Set the desired range of control for each of the operator parameters, and which of the control functions to vary the operator effects, if any. Set output envelope shape parameters and which of the control functions will vary the en- velope effects, if any. Then play.... Morris G. Miller 9 MINI MIDI LESSONS 12Aug89-MGM G L O S S A R Y After touch pressure - The pressure placed on a key after the key is down. Often used to control tremolo or vibrato in the voice. Not all keyboards send after touch information; not all synthesizers respond to that information; not all se- quencers will recognize it. Attack velocity (key) - The rate, or how quickly, the key is pressed down. Generally used to control the volume, or loudness, of the tone when played. Not all keyboards send attack velocity; not all synthesizers respond to that infor- mation. Audio mixer - A set of low-level amplifiers and gain controls (volumes) to combine a number of stereo inputs into one stereo amplifier and speaker system. Each input level may be adjusted separately and a master output level may be set for the signal to the amplifier. Meters may be provided for monitoring the output levels. Headphone jacks allow listen- ing to the mixed result. Channel - The "address" of a MIDI message. Each instrument voice can be set to one of sixteen MIDI channels so that only it receives the MIDI codes sent to it. See also, Omni. Control codes - MIDI codes which duplicate the settings of the control devices of the keyboard such as the modulation wheel, pitch bend, foot switches and pedals, etc. Daughter - The person who knows how to play a keyboard. Drum machine - A special kind of sequencer which may be loaded with patterns to play drum sounds and rhythms. Very much like the rhythm sounds built into many of the low-end keyboards, except that you define the drum patterns before loading them into the machine. Performance of patterns and rhythms may be changed during play. In some machines you define the sound (type) of the drum. Editor - The program, or function module of a sequencer, which allows viewing and changing of notes, attack velocity, dura- tion, and other parameters of a song. The editor will generally be a part of the sequencer, and allow the entry of notes (writing the song) for performance, and possibly printing the song score. Entremont, Philippe - a French pianist with his own interpreta- tion of Chopin, no better than my own - or yours. Envelope - The shape of a note's output, or that of the operators which make up the note. Portions of the envelope may may be defined to control the sound response of the tone, and in part the timbre (tone quality) of the sound. Exclusive codes - Codes not specifically defined by the MIDI standards, used by manufacturers to do things "their way". This is necessary because no two keyboards are exactly the same nor have the same features. Glissando - A rapid slide up or down the musical scale. See also Portamento. Instrument (musical) - Any of the instruments which produce musi- cal sounds by MIDI, or generate the MIDI signals for control of other instruments. Some of the instruments which are now equipped to produce MIDI codes are keyboards, reed (wood), guitar, piano, and horn (brass). 10 MINI MIDI LESSONS 12Aug89-MGM G L O S S A R Y Key signature - The sharps and flats symbols placed following the clef symbol on a musical staff. Each sharp or flat adjusts the natural pitch of the note indicated by one half-tone. Keyboard - A musical instrument with keys similar to that of a piano, but used to generate the MIDI codes for performance of a song. Assumed to reproduce sound by synthesis or voice sampling and, thus, may not sound anything at all like a piano. Librarian - A utility program, generally used with the sequencer, to load and store voice parameter setups for the synthesizer or sampler. As such, it allows new voices to be performed, as needed, by each song. Local features - The sounds, rhythms, and chords which may be played on the keyboard (or other instrument) which do not generate MIDI codes for recording and play back. Measure (musical) - The time duration between two bars of music as indicated by the time signature of the song. See also, Time signature. MIDI - The interface standard for interconnecting musical instru- ments and related equipment. What these lessons are all about. MIDI IN - The MIDI port the instrument "listens" on. If the MIDI code channel number matches the setting of the instrument voice, the instrument will perform by those codes received on the MIDI IN port. MIDI OUT - The MIDI port the instrument "talks" on. All MIDI data sent by the instrument will be on this port, including performance (as from a keyboard) and parameters (as when sending voice definitions). Data received on MIDI IN will not be repeated on the MIDI OUT. MIDI THRU - The MIDI port which repeats everything received on the MIDI IN port, down to the next instrument in the MIDI system. Data sent by the instrument will not be sent on the MIDI THRU port. Not all instruments have a MIDI THRU port. Mixer - see Audio mixer. Modulation (envelope) - see Envelope. Modulation wheel - A keyboard control to vary at some predeter- mined rate the amplitude (volume) or frequency (pitch) of the note(s) played, or of one or more operators of the note composition giving a tremulous effect of vibrato. Monophonic - All the sound coming out for only one ear at a time. Neeeet - see MIDI. Note (duration) - Each note, and rest, has a shape (shade and stem) to indicate the time duration given to the note rela- tive to the time of the measure indicated in the time signa- ture. In MIDI, 96 clock 'ticks' is the duration of one quarter-note, therefore an eight-note has 48 MIDI clocks and a sixteenth-note has 24, etc. The rate in which these occur can be adjusted by the tempo set to the song. Note (musical) - A musical note is unique by its frequency and relation to the root of a musical scale. For every position on a staff (lines and spaces) there is only one note, and it has a given frequency. That note relates directly to one key on the keyboard. See also, Scale. 11 MINI MIDI LESSONS 12Aug89-MGM G L O S S A R Y Note (on/off) - The MIDI instrument will send a MIDI code when a key is pressed (note on) and when the key is released (note off). Associated with this code may also be code informa- tion on how quickly (velocity) the note is pressed or released. Not all keyboards send velocity information, or of both types. Octave - An interval of 8 diatonic degrees; a harmonic interval. The musical scale is divided into 12 semitones (half steps), beginning at the root note indicated by the key signature. These notes correspond directly to a position on the keyboard and the 12 notes (black and white keys) in se- quence. The relative position, frequency, or pitch of a note and the corresponding note 12 tones higher is one oc- tave. Your keyboard may span from 3 to 8 octaves. Omni - MIDI codes are "addressed" so that a voice may receive only the codes intended for it. A voice or control may also be set to omni (all around) to receive any MIDI code without regard to the MIDI channel address. This may be useful when all voices are to respond equally to the modulation wheel or foot pedal. Operator (synthesis) - Synthesizers combine 2 to 8 separate tone generators, each having a defined shape, amplitude, attack rise, decay, etc. Each such tone is called an operator of the voice composition. The number of such tones and the manner in which they are combined determines how faithfully a given sound may be created. Orchestra - see Neeeet. Pan - Stereo balance controls. In some machines the pan control simply switches from stereo to monophonic. In others, one or more sounds may be made to pan from left to right during play, sounding, for example, a motorcycle whizzing down the street - or other sounds more subtle. Patch (MIDI) - The selection of voices and performance parameters for song play. Some instruments allow the patch to be re- corded with the song and sent by MIDI code as performance begins. Pawn shop - dealer in musical instruments. Pedal (mute, soft) - An accessory input to the keyboard for addi- tional performance control. Often used in the same manner as the pedal controls on a piano, but voices may be created to respond to the pedal in any of the voice parameters al- lowed by the synthesizer. Pedal (sustain) - An accessory input to the keyboard for addi- tional performance control. This device is a switch, and used only in voice parameters for on/off control, such as sustain (reduced note decay). Performance (musical) - The playing of a song, but often much more than just that - all of the MIDI controls placed on the song, including voice selections, section repeats, tempo ad- justments, etc. Performance voices - Many synthesizers allow individual voices to be combined into performance buffers. For example, six trumpets may be combined, each very slightly offset in 12 MINI MIDI LESSONS 12Aug89-MGM G L O S S A R Y various ways (not all sounding exactly the same), and played as one instrument voice. Call it a "chorus of brass". Call it a performance voice. Pitch (note) - The frequency of the note or its position in the musical scale. See also Note (musical). Pitch bend - A control on some keyboards which will shift the pitch (frequency) of all notes played, up or down. As the pitch bend wheel is operated, MIDI codes are sent which may be recorded, edited and replayed with the performance. Not all keyboards support pitch bend. Portamento - A glide from note to note, as with a trombone or violin. Accomplished on the keyboard with the pitch bend wheel or foot pedal. The voice of the synthesizer must be created with operators which respond to the desired control. Punch-in - A song recorded in real time may contain mistakes in the performance. Punch-in allows the performer to listen to the music on play back, play with the music, and then, at the right time, the sequencer will replace predefined measures of the recording with what the performer is now playing. Not all sequencers allow punch-in. Range (keyboard) - See Octave. Real time - At the time of playing, at performance tempo. All sequencers allow recording in real time. Some allow entry by punch-in and some by step entry, or both. (See also punch-in and Step entry. Recorder (MIDI) - The MIDI sequencer is, typically, organized like a tape recorder. It has tracks for recording segments of the song, tracks for editing, copying, etc. It will have a play button, rewind, position counter, and other "features" of a tape recorder. See also sequencer. Recorder (sound) - A common audio recorder, useful for playing the MIDI performance while singing. With an audio mixer, and a little practice at dubbing, great things can be done. Not all recorders are equal. Most recorders are 2-channel, 4-track; which means only two channels of music can play at the same time (and must!) Some recorders have 4 to 8 chan- nels, with or without SEMPTE control. With these recorders an entire orchestra may perform. Register (musical scale) - Your keyboard can span a number of oc- taves. The note 'C' in the middle of your keyboard is the first note of the third register. It and all the notes up to the next 'C' (exclusive) are notes of register three. Middle-C is then called C3. The octave above is register 4 and the octave below register 2. Your keyboard might span from G-2 (minus 2) up to G8. Probably not. Release velocity (key) - The rate, or how quickly, the key is released. Sometimes used to control portamento or glissando of the tone when played. Not many keyboards send release velocity. not all synthesizers respond to that information. Rhubarb - a red, woody weed used to make pies only one semitone better than mud pies. Rhythm machine - Like drum machines, a special sequencer which may be loaded with patterns to play drum sounds and rhythms, in the same manner as rhythm sounds built into many of the low-end keyboards, except that you define the patterns 13 MINI MIDI LESSONS 12Aug89-MGM G L O S S A R Y (unfortunately the drum and rhythm patterns of these keyboards are not generally available under MIDI control.) MIDI Performance of patterns and rhythms may be changed during play. The pattern played may be chord sequences as well as other sounds. See also Drum machines. Sampler - A type of sound generator which stores an actual sample of the voice, taken with a microphone. The digitized sound, when played, is reconstructed to the frequency of the desired note using the original sound parameters as closely as it can. See also, Sound generation. Scale (musical) - The contemporary scale of today is the division of one octave into the 12 harmonically related intervals called half tones (half steps) and the formation of harmonic intervals (notes played simultaneously) we find pleasing to the ear. Music theory has defined certain of these inter- vals acceptable to the ear in melodic interval (played one after the other). See also, Octave, Scale. Score - The printed, graphical, notation of the music perfor- mance. The score gives information on the scale in root, all the individual notes to be sounded, tempo and timing of all notes, composer's comments on force and mood of the per- formance, and just about anything else necessary to reproduce the sounds of the performance. Scorer - A module or program to print the score of a musical per- formance held by the sequence editor in MIDI form. Semitone - The smallest interval of the musical, or chromatic, scale. Also called the half-step. The major and minor scales are actually composed of seven of these notes in com- binations of steps and half-steps (dual semitones and semitones). All of the semitones are available to the com- poser by use of markings in sharps and flats symbols to raise or lower by one halftones the normally occurring note of the root scale. See also, Scale. SEMPTE - An acronym for the Society of Motion Picture and Televi- sion Engineers. A timing standard, similar to MIDI, based on the framing of television and motion picture video infor- mation. Sequencer - The computer program for recording, editing and replay of a musical performance. See also, Editor. Serial - Data sent bit-by-bit, one after the other. Sound generation - The production of (musical) sounds by any of a number of digital electronic processes. Sometimes simply called "sound synthesis", as in "synthesizer". There are a number of ways to produce musical sounds today, other than sound synthesis. The most common is digital sound sampling (see Samplers). Others manufacturers may use pulse modula- tion techniques, harmonic mixing and filtering techniques, or any of a number of other procedures, sometimes in blended combinations. Staff - The five lines and enclosed spaces of common musical notation. When given a tonal range by the clef symbol, each note position then has definite tone name and frequency. 14 MINI MIDI LESSONS 12Aug89-MGM G L O S S A R Y Step entry - A procedure where notes may be entered by the keyboard one note (or combination of notes) at a time, rather than by continuous playing. Not all sequencers per- mit step entry. See also, Real time entry. Stereo - All the sound coming out for both ears at the same time. Sustain - To cause a note to continue sounding beyond note off, or to increase the time in which it decays. Normally ac- complished with a foot switch during performance, but may be edited in the sequence editor, as well. This effect must be programmed into the voice when created in the synthesizer. Synthesizer - A type of sound generator which combines a number of operators having specified parameters to produce a com- plex audible waveform. The word "synthesis" comes from the fact that there is one master oscillator and all other tone frequencies are generated as signals harmonically related to that one master. See also, Operator. System codes - See Exclusive codes. Tape sync - The signals produced by some MIDI control "boxes" to record the MIDI clock on a tape recorder with the perfor- mance. Once recorded, the recorded clock becomes the "conductor" for other performances, thus allowing multiple recordings which all play together properly. Not all se- quencers support SEMPTE or tape sync. Tempo - The speed of a performance. The number of quarter notes per second, as in a tempo of 110. See also, Note(duration). Time signature - A two-part notation designating the number of (numerator) time units (denominator) per musical measure (between bars.) A notation of 3/4 time says that there will be three quarter notes per measure. Tonal position - On a staff marked with a clef, the name and tone frequency of a note. Also sometimes in reference to the relative position of a note within the associated scale. See also Octave, Note (musical) Touch pressure - see after touch pressure Touch sensitivity -The parameters, related to pressing a key on a keyboard, which are measured and sent by MIDI for recording and control. See also, Attack velocity, After touch, Release velocity. See also, Lesson #5. Track - A buffer of the sequencer for recording, editing and per- formance of a song segment. See also, Recorder(MIDI). Transpose - To move notes of a song (segment) up or down in fre- quency by a specified interval of semitones. Tremolo - A tremulous effect put upon a voice performance by modulation of the amplitude, frequency, or of one or more of the operators of the voice composition. Often used in reference to the amplitude modulation, but musically this is not specific. With MIDI, most often accomplished with the modulation wheel control. See also, Modulation (wheel), Vibrato. Vibrato - A tremulous effect put upon a voice performance by modulation of the amplitude, frequency, or of one or more of the operators of the voice composition. Most often used in reference to the frequency, or tone modulation. With MIDI, most often accomplished with after touch control. See also, After Touch, Tremolo. 15 MINI MIDI LESSONS 12Aug89-MGM G L O S S A R Y Voice - The defined sound produced from a synthesizer or sampler, commonly supposed to resemble that of a conventional musical instrument or sounds which follow rules found in nature. The voice is not necessarily musical. Since the word in- strument is used to refer to the devices in MIDI, the word voice is used to refer to the sound the devices produce. Yard sale - outlet for pawn shop rejects. Morris G. Miller 16