map
A table in which input values are assigned to outputs arbitrarily by the user on an item-by-item basis.

matrix modulation
A method of connecting modulation sources to destinations in such a way that any source can be sent to any combination of destinations.

MCI
Media control interface. A multimedia specification designed to provide control of onscreen movies and peripherals like CD-ROM drives.merger: A MIDI accessory that allows two incoming MIDI signals to be combined into one

MIDI
Short for "Musical Instrument Digital Interface"; MIDI enables synthesizers, sequencers, computers, rhythm machines, etc. to be interconnected through a standard interface and exchange music related data such as notes, controller messages, clock and sounds. MIDI dictates a uniform data format and connector standard for all manufacturers.

MIDI clock
A timing reference signal sent over a MIDI cable at the rate of 24 clock pulses per quarter-note (ppq).

MIDI Interface
A hardware interface that is either inserted into one of the computer's internal expansion slots or plugged into a computer (serial/parallel) port. It allows the computer to communicate with other MIDI instruments by adding one or more MIDI input and output ports.

MIDI Mapper
A Windows applet that automatically maps (shifts the value of) channel, program change, and note numbers. For example, a map could cause all notes coming in on MIDI channel 3 to go out on MIDI channel 7.

MIDI mode
Any of the ways of responding to incoming MIDI data. While four modes -- omni off/poly, omni on/poly, omni off/mono, and omni on/mono -- are defined by the MIDI specification, omni on/mono is never used, and at least two other useful modes have been developed -- multi mode for multitimbral instruments and multi-mono for guitar synthesizers.

MIDI Out/Thru
A MIDI output port that can be configured either to transmit MIDI messages generated within the unit (Out) or to retransmit messages received at the MIDI In (Thru).

MIDI output
A device that translates MIDI data from one form to another in real time.

MIDI thru
There are two types of MIDI thru:
a) One, a simple hardware connection, is found on the back panels of many synthesizers. The thru jack in this case simply duplicates whatever data is arriving at the MIDI in jack.
b) Sequencers have a second type, called software thru. In this case, data arriving at the in jack is merged with data being played by the sequencer, and both sets of data appear in a single stream at the out (not the thru) jack. A software thru is useful because it allows you to hook a master keyboard to the sequencer's MIDI input and a tone module to its output. You can then play the keyboard and hear the tone module, and the sequencer can also send its messages directly to the tone module.

Mixer
A hardware or software device that combines multiple audio signals into one destination signal. Mixers usually provide control over the volume and/or stereo balance of each source signal.

MME
Short for "Multi Media Extensions"; Windows' standardized software; interface for multimedia applications.

Modulation
The fast oscillation of one or more operators or sound waves of a synthesized sound. Commonly used in FM synthesis to add some complexity and texture to a sound. Many MIDI controllers and keyboards provide a specific wheel or slider for controlling the modulation of an instrument sound (often referred to as the mod-wheel).

Module
A hardware sound generator with no attached keyboard. A module can be either physically separate or integrated into a modular synthesizer, and is designed to make some particular contribution to the process of generating electronic sound.

mod wheel
A controller, normally mounted at the left end of the keyboard and played with the left hand, that is used for modulation. It is typically set up to add vibrato. > modulation, > vibrato.

Monophonic
Only one note of an instrument may be played at a time. An instrument that can play many at once is said to be polyphonic. Monophonic instruments usually cut-off the sound of previously played note with the start of new one.

Monotimbral
Only one instrument sound (timbre) may be played at a time. Older synthesizers were often monotimbral before sequencers where invented, which enables musicians to play multiple parts on the same instrument. A monotimbral synthesizer may be able to play multiple notes of the one instrument sound simultaneously.

MTC
MIDI time code. MTC is a way of transmitting SMPTE timing data over a MIDI cable. > SMPTE time code.

multi mode
A MIDI reception mode in which a multitimbral module responds to MIDI input on two or more channels and maintains musical independence between the channels, typically playing a different patch on each channel.

Multisample
The distribution of several related samples at different pitches across the keyboard. Multisampling can provide greater realism in sample playback (wavetable) synthesis, since the individual samples don't have to be transposed over a great distance.

Multitimbral
More than one instrument sound (timbre) may be played at the same time. Most modern synthesisers, samplers and sound cards have this capability. A musical device that is not multitimbral is said to be monotimbral.