MIDI Glossary

Glossary of Basic MIDI Terms

General MIDI - General MIDI (GM) is a standard developed by Roland, and adopted by most other synth manufacturers, to make MIDI files sound similar on different synths, and to allow easier control of one synth from another. General MIDI files and compatible MIDI devices use the same program (or "patch") number for the same instruments. There are 128 GM sounds (programs or instruments), grouped by instrument type, (i.e. piano sounds, organ sounds, strings, etc.). This way MIDI files can be arranged to request the same type of sounds from any compatible playback device. They may don't sound exactly the same, better synths will generate better sounds, but at least if your file calls for a piano sounds, that's what you'll hear. There are many different manufacturers and many different models of GM synths, sound modules and sound cards, and the same MIDI file may sound better on one than the other, but piano will be piano, and strings will be strings.
MIDI ADAPTER - The Sound Card MIDI Adapter Cable is a special cable designed to connect MIDI devices to the joystick port of MIDI capable sound cards. Many new computers are sold without sound cards, and not all sound cards are MIDI capable, so having a joystick port on your computer doesn't necessarily mean that you can connect MIDI devices to it. Before you buy a MIDI adapter cable, check your computer if it's equipped with the proper sound card.
MIDI CABLE - The standard cable to connect MIDI devices. Comes in various lenghts, (normally between 1 and 20 feet) with 5-pin DIN connectors on both ends.
MIDI CHANNEL - Most MIDI instruments (synthesizers and sound modules) are capable of generating multiple sounds (instruments) at the same time. Each of these instrument can be assigned to their own channels. The basic MIDI synth has 1 port = 16 channels, but there are also 32 and 64 channel synths available. Channels can be considered as parts in a music score or instruments in an orchestra, or as separate tracks in recording. MIDI sequencers can take advantage of multiple channels, and even multiple synthesizers, creating complex arrangements for bands, even for a large symphonic orchestra.
MIDI CONTROLLER - MIDI controllers are electronic devices capable of generating and sending MIDI data. The most commonly used controllers are MIDI keyboards. There are also many different controllers available for sending various MIDI control messages to synthesizers and sound modules, as well as MIDI sequencers. These devices are used for controlling volume on multiple tracks, and to change sounds, etc. See MIDI data for details.
MIDI COUPLER - Commonly used for connecting standard MIDI cables to each-other, to create an extension. This is what you need to make a 10ft. cable out of two 5ft. cables.
MIDI DATA - MIDI data is the information transmitted by MIDI devices. It includes the note names (i.e.C#4, F5, etc.), note duration, velocity, volume, program change, and many other performance control messages. MIDI data can be transmitted directly from controllers to synthesizers and sound modules, or recorded to MIDI sequencers, edited and played back on synths and sound modules.
MIDI DEVICE - Any hardware or software synthesizer, sampler, sound module, drum machine, interface, controller, etc., capable to send and/or receive MIDI data.
MIDI FILE - MIDI files or MIDI sequences are special files to store MIDI data created by MIDI sequencers. MIDI files usually have a .mid extension, (unless they are saved in the proprietary extended format of the sequencer program). MIDI files don't contain any sounds (like .WAV files) so in order to play them, you need not only a MIDI player or sequencer program, but also a synthesizer or sound module to generate the sounds. MIDI files only contain performance data, and instructions on what sounds to play. The most widely used format for MIDI files is General MIDI (GM), recognized by most MIDI players and synths. You'll find thousands of GM files on the web, start your search at the MIDIWORLD library.
MIDI IN, OUT, THRU - MIDI IN, OUT and THRU are the names of MIDI ports on MIDI devices. The MIDI IN port is used to receive MIDI data from the OUT or THRU port of other devices. THE MIDI OUT port is for sending data to the IN port of other devices, and the THRU port provides an extra connection for additional devices. The THRU port will simply pass on the data received from the IN port to other devices, while the OUT port will only send data generated by the device.
MIDI INTERFACE - MIDI interfaces are used to connect MIDI devices to computers.
MIDI KEYBOARD - MIDI controller keyboards are electronic keyboards, designed to trigger sounds in synthesizers and sound modules, as well as to enter notes into MIDI sequencers. There's a microswitch under each key connected to a MIDI processor. It will sense what keys are pressed, how long they are held, and sends this data to other devices. Velocity sensitive keyboards will also sense how hard the keys are pressed, to add dynamics to the note data. Some keyboards have an extra sensor for aftertouch, for added expression. When the key is held down, you can apply more pressure to trigger the aftertouch sensor. This aftertouch data can be used to alter the sound (i.e. add vibrato). Most controller keyboards are also equipped with pitch and modwheel and various other knobs, sliders and buttons to send MIDI data, such as program change, and other assignable control messages to the receiving MIDI devices. MIDI controller keyboard usuall don't come with built in sounds, (if the do, they are called synthesizers).
MIDIMAN - Midiman is the manufacturer of MIDI interfaces, MIDI controllers, and many other useful products for computer music. The company name is now M-Audio.
MIDI PORT - MIDI ports are the 5-pin connectors on MIDI devices labeled as MIDI IN, MIDI OUT and MIDI THRU. Each MIDI port can transfer 16 discrete channels of MIDI data, controlling as many instruments on one or more modules. The use of computers and MIDI sequencers allow the use of multiple MIDI ports, controlling lots of instruments on lots of modules at the same time thru MIDI interfaces. It's like having a band, an orchestra, and then some...
MIDISPORT - Midisport is a popular line of USB MIDI Interfaces by Midiman / M-Audio.
SAMPLER - Samplers are very similar to synthesizers, with the ability to add or create custom samples. Samples are digitally recorded sounds of actual instruments, human voice or any kind of noise you like. These samples can be triggered from MIDI sequencers or MIDI keyboards.
MIDI SEQUENCER - MIDI sequencers are software or hardware recorders of MIDI data. Some synthesizers have built-in sequencers, and there are also dedicated sequencer boxes. Hardware sequencers are portable, but limited. Software sequencers on the other hand require a computer, but they are very powerful, and easy to use. They offer many editing options, and graphical user interface. You can use them to record, arrange and play your music, and also to create printed sheet music.
MODWHEEL - The modwheel or modulation wheel is a controller wheel used on synthesizers and MIDI controller keyboards. It can be assigned to control the sound many ways, in real time.
PITCH WHEEL - The pitch wheel or pitchbend wheel is a controller wheel used on synthesizers and MIDI controller keyboards. It's a spring-loaded wheel, you can use it to change the pitch of the note up or down in real time.
SOUND MODULE - Sound modules are synthesizers with no built-in keyboards or other triggering devices. Thanks to MIDI, they can be triggered remotely from controllers, like keyboards, computers, even special guitar and wind controllers. One keyboard or computer may control several modules via MIDI cables connected to MIDI ports on both ends.
SYNTHESIZER - Synthesizers come in many shapes and forms, with one thing in common : they all generate sounds electronically. We can differentiate between synthesizers by the method they use to create sounds. Some of them use digitally sampled sounds of other instruments, we call these "sample playback synths". The first synthesizers were based on voltage regulated analog circuitry, using oscillators to create basic waveforms, and alter them by various filters and other modulators to come up with all kinds of unique sounds. There are so many combinations of old an new technolgy, and so many synthesizers, we dedicated an entire website to the subject, please visit Synthman.com. You'll find lots of info on synths, and if you have any synth related questions, feel free to ask at the Synthesizer Forum or the MIDI Forum.