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MIDI Glossary



Active Sensing

Active Sensing is a process by which MIDI devices can monitor an active connection with other MIDI devices. This message is sent regularly at specific intervals.


An address is literally a "location". For electronic devices, an address is a location in memory. Values can be read from addresses in Read Only Memory (ROM), while values can be read from and written to addresses in Random Access Memory (RAM).


Aftertouch is a message which indicates how much pressure is applied to the keyboard after the note has/notes have been played. There are two types of aftertouch, Channel Aftertouch which is a single value for the entire channel, and Key Aftertouch which are separate messages for each key pressed.
These values can be used to control an effect, for example vibrato. On the Roland Sound Canvas, a SysEx message is required to specify what happens when aftertouch messages are received. By default, these messages do nothing.
Aftertouch messages are Channel Messages.
These messages are also known as Channel Pressure, Channel Key Pressure and Polyphonic Key Pressure

All Notes Off (CC 123)

This message will stop all currently playing notes in a channel unless hold or sostenuto are on, in which case it is ignored.
This is a channel message.

All Sounds Off (CC 120)

This message will unconditionally stop all currently playing notes in a channel.
This is a channel message.


See envelope.


Bank (CC 0)

In Roland terms, a bank is the same as a variation and is used interchangeably in the manual.
The Bank message is a Channel Message.

Bulk Dump

Use bulk dump to retrieve the values from a large block of addresses with a single SysEx request message. The MIDI device manual should identify what bulk dump options are available and what the request message is to obtain them.


Capital Tone

This is simply the first instrument in each bank , where the variation number is zero.
There are one hundred and twenty-eight capital tones.


MIDI messages are transmitted via a single cable. To be able to play notes on different instruments, the idea of a channel is used. MIDI messages intended for a specific channel have the channel number encoded in the message itself. Because of the size of the MIDI message, there is a maximum of 16 MIDI channels.
To overcome this limitation, ports are used to address groups of 16 channels.

Channel Aftertouch

See Aftertouch

Channel Message

A "Channel Message" is a MIDI message that is intended for a specific channel.
A Channel Message is made up of three parts. The first part identifies the type of MIDI message and what channel the message is intended for. The next two parts have different functions depending on the type of MIDI message.
Most MIDI messages fall into this category. SysEx messages are independent of channel and are of variable length.

Channel Pressure

See Aftertouch


Chorus is an effect which makes a sound "fatter" by making it appear that the sound is coming from more than one source, hence "chorus".

Coarse Tuning

Coarse tuning is the process of changing the tuning of an instrument in semitones (half-steps).
Master Coarse Tuning (controlled with RPN) is used to change the tuning of an entire channel, as opposed to scale tuning which adjusts individual notes.
See also Fine Tuning

Continuous Controller

See controller.

Control Change (CC)

Control change is a MIDI message that changes the state of a controller. There is room for 128 types of control change messages, however not all are assigned by the standard MIDI specification and furthermore, not all synthesizers support all controllers. Control change messages are often referred to by the letters CC and the number of the controller, e.g. volume is "CC 7".
Control change messages are channel messages.


A controller is something that controls a function in a MIDI device. The most obvious example is volume, however there are many others. Some controllers have a physical control on the MIDI device, like pedals, knobs, levers and sliders. Changing the position of the control sends control change messages on a specific MIDI channel.

Cutoff Frequency

The cutoff frequency is used to alter the way we hear a sound. A low pass filter is used to specify the point at which frequencies are cutoff, allowing only lower frequencies to be heard. A high cutoff frequency, will make a sound seem brighter. A low cutoff frequency will make a sound seem dark or dampened.


Daisy Chain

A daisy chain is the term used when connecting multiple MIDI devices together. The MIDI Out connector of the first device is connected to the MIDI In connector of the second device. The MIDI Thru connector of the second device is connected to the MIDI In connector of the third device and so on.
Using a daisy chain allows you to control multiple MIDI devices from a single source, whether it be a sequencer or a keyboard. Since most devices will respond to MIDI data on all sixteen channels, it would be necessary to mute certain channels on each device so that only one device responds to specific channels, unless you want to use layering.

Data Entry (CC 6 and CC 38)

The Data Entry controllers are used in conjunction with RPN and NRPN messages. Once an RPN or NRPN parameter is selected, these controllers are used to modify that parameter.
For examples, see the RPN and NRPN tutorial.


See envelope.


Delay is an effect which creates an echo or echoes, depending on the setting.

Device ID

The Device ID of a synthesizer is only useful when you have more than one of the same synth in a daisy chain. To be able to send system exclusive messages to specific synthesizers of the same type in a daisy chain you would first have to change each of their Device IDs. Only the synthesizer with the matching Device ID would respond to the system exclusive message.

Drum Part

Each part in a Sound Canvas can either be a "normal part" or a "drum part". A normal part plays different notes on a single instrument. A drum part plays a different rhythm (percussion) instrument on different notes.
Some Sound Canvases can have more than one drum part.

Drum Set

A drum set is a collection of specific rhythm (percussion) instruments used on the drum part. There are a limited number of percussion instruments available in a drum set, thus different drum sets allow access to different percussion instruments.
Use a patch change message on the drum part to change the drum set.

English Horn


This is exactly what the name implies. It is a process that is applied to a sound to create an effect.
The most common effects found in synthesizers are
chorus and reverb, however there are many others.


The envelope of a sound is the shape a sound makes when represented visually. An envelope has four parts: attack, decay, sustain and release. The envelope of different sounds varies considerably.
The attack part is the first audible part of a sound when a note is played on an instrument. It goes from silence to the maximum volume of the note.
The decay part is when the sound loses some volume after the attack.
The sustain part is heard for as long as the note continues to play. Some instruments can sustain a note indefinitely (like an organ) while others fade to inaudibility.
The release part occurs when the note is release and the sound fades to silence.

Expression (CC 11)

Expression is used in conjunction with level (CC7) to control the volume. Level is used to set the maximum volume for the channel, while expression is used to vary the volume up to the limit set by the level.
Expression is a Channel Message.

Fretless Bass

Fine Tuning

This is used to adjust the pitch of an instrument in small steps. You can use a different tuning for each part.
Master Fine Tune (controlled with RPN) is used to adjust the pitch of the entire channel, as opposed to Scale Tuning which changes individual notes.
See also Coarse Tuning.

Gamelan Gong

General Midi (GM)

Before the GM standard was introduced, different synthesizers seldom had the same instrument on the same Patch Change (PC) number. When a MIDI file sequenced for a particular synthesizer was played back on a different synthesizer most, if not all the instruments would be wrong. While PC 1 on one synthesizer could be "Piano", on another it could be "Violin" and on yet another it could be a sound effect!
GM is, in essence, a standard that specifies what instrument corresponds to each of the one hundred and twenty-eight PC numbers. It also specifies that the percussion channel is channel 10 and which notes on the percussion channel correspond to which percussion instrument. In theory, a GM sequence should sound the same on any GM compliant synthesizer.
For full details on the GM specification, have a look at the MIDI Manufacturers Association web site.

General Standard (GS)

GS is Roland's standardized specification, which is a superset of GM. This means it is GM compliant, but goes further than GM in its specification of how MIDI messages are processed by a MIDI device. In theory, a GS sequence should sound the same on any GS compliant synthesizer.
Because of the popularity of GS, more of its features have been incorporated into GM.



Decimal is a numbering system that uses ten digits, 0 through 9. Binary is a numbering system that uses two digits, 0 and 1. Hexadecimal is a numbering system that uses sixteen digits, 0 through F. Hexadecimal is a convenient numbering system when working with data used by electronic devices such as computers and synthesizers.
To understand System Exclusive Messages you will need to understand hexadecimal, so have a look at the Hexadecimal Tutorial.

Hold (CC 64)

The "Hold" Control Change message is the MIDI equivalent of a piano's sustain pedal. This message switches the sustain on or off depending on its value.
Hold is a Channel Message.

Ice Rain

If you can find a musical application for this Roland Sound Canvas instrument, I would like to hear it!


In MIDI terms, an instrument is anything that produces a sound. Apart from the expected musical instruments you will often find a whole selection of sound effects like animal and machine sounds.
Different synthesizers use different methods to produce the sounds. Some synthesizers can produce acoustic sounds much better than others.
Each MIDI channel can play only one instrument at a time.
The patch change (PC) message and variation (CC 0) are used to select the desired instrument within a map.

Jew's Harp


Key Pressure

See Aftertouch

Key Shift

Key shift allows you to transpose a channel in steps of semitones (half-steps) up to a maximum of two octaves above or below normal. This is a quick and easy way of transposing a sequence without changing every note.
There is a master key shift and a key shift for each channel.

Lequint Guitar


Playing the same notes on multiple instruments simultaneously is called "layering". This effect can be achieved by copying one track in a sequence and pasting it into another track to be played on another channel using a different instrument.
The Roland Sound Canvas can achieve layering much more easily by assigning the same MIDI channel to multiple parts.

Level (CC 7)

In MIDI terms, when referring to level, one is usually referring to the volume level. There are two types of level: Master Level and Channel Level (CC 7).
Master Level is used to adjust the total output volume of the synthesizer, while Channel Level is used in conjunction with Expression (CC 11) to adjust the volume of individual channels, and is therefor a Channel Message.

Local Control (CC 122)

Local Control can be turned on or off. When it is on, a MIDI device can be controlled with its built-in keyboard. When it is off, the MIDI device will only respond to MIDI messages received through MIDI In, locally played notes are ignored.

Low Frequency Oscillator (LFO)

A low frequency oscillator is used to cyclically change something, for example pitch, creating vibrato. The frequency (speed) and the depth (amount) of the oscillation can be changed. LFO is often used with TVF and TVA to create effects.

Low Pass Filter (LPF)

A low pass filter is used to filter out higher frequencies in a sound so that only the lower frequencies can be heard. The point above which the frequencies are filtered out is known as the cutoff frequency.


Map (CC 32)

In Roland terms, a map is a set of all instruments that belong to a synthesizer. For example, the SC-88 Map has more instruments than the SC-55 Map.
It is important to be specific about which map you're selecting an instrument from, as is indicated in the tutorial Selecting Roland Capital Tones and Variations
Map is a Channel Message.

Master Coarse Tune

See Coarse Tuning.

Master Fine Tune

See Fine Tuning.


MIDI stands for Musical Instrument Digital Interface. It is a standard for connecting instruments together and for exchanging MIDI messages.

MIDI Implementation Chart

A MIDI implementation chart is a chart specifying what MIDI messages a MIDI device can send (transmit) and which it can receive (recognize).


MIDI In is the physical connection where a MIDI device receives MIDI messages. MIDI In is connected to another MIDI device's MIDI Out or MIDI Thru.

MIDI Message

MIDI messages are used to exchange data with MIDI devices. There are many of types of messages ranging from control messages to note messages.


MIDI Out is the physical connection through which a MIDI device sends MIDI messages. MIDI Out is connected to another MIDI device's MIDI In.


MIDI Thru is the physical connection through which a MIDI device sends all MIDI messages that it receives through MIDI In. This is used to daisy chain multiple MIDI devices.

MIDI Time Code (MTC)

MIDI Time Code is part of the standard MIDI specification. It is a means by which connected MIDI devices can synchronize with one another.


There are four Modes in MIDI:
Mode 1: Omni On, Poly
Mode 2: Omni On, Mono
Mode 3: Omni Off, Poly
Mode 4: Omni Off, Mono

Modulation (CC 1)

Most MIDI keyboards have a modulation wheel or control. By default, the response to this controller is to add vibrato to the playing notes, however it can be re-assigned to control other effects.
Modulation is a channel message.

Mono (CC 126)

If the Mono MIDI message is sent to a channel, only one note can be played at a time on that channel. This is useful for instruments that cannot play chords.
Mono is a channel message.
See also Poly (CC 127).


Multitimbral is the term used for a MIDI device that can simultaneously play more than one timbre.


Mute means "silent" or "to silence". It is used when you want to silence some channels while listening to others.

Nylon String Guitar

Non-registered Parameter Number (NRPN) (CC 98 and CC 99)

NRPNs are messages that can be used to modify sound parameters in a synthesizer. For example, vibrato can be adjusted using NRPN on the Roland Sound Canvas.
NRPN messages are used to select the desired parameter and then data entry messages are used to change the selected parameter.
Unlike RPN, NRPN is not part of the standard MIDI specification and therefor is not necessarily consistent across synthesizers.
NRPN messages are Channel Messages.
For examples, see the RPN and NRPN tutorial.


A note is a sound you can hear. In MIDI terms a note is switched on and off to produce sound. The Note On Midi message has pitch and velocity. A Note On message with a velocity of zero is the same as a Note Off message.
Note On and Note Off are channel messages.


Omni Off (CC 124)

When Omni is switched off a MIDI device will only receive MIDI messages on one channel.

Omni On (CC 125)

When Omni is switched on a MIDI device will receive MIDI messages on all channels.


Pan (CC 10)

Use Pan (CC 10) to place an instrument in the stereo field. Lower values will be closer to one speaker, while higher values will be closer to the opposite speaker. Each channel can only be at one pan position at a time, however you can change that position as often as you like.
Pan is a Channel Message.


A parameter is simply a value. Most MIDI messages have one or two parameters, for example Note On has two parameters: pitch and velocity.


The Roland Sound Canvas is a multitimbral MIDI device. This means it is capable of simultaneously producing the sounds of multiple instruments. To do this it uses Parts to encapsulate each instrument. Each Part is similar to a MIDI channel in that it can play only one instrument at a time. It can also be set up with individual effects settings.
Where a Part differs from a Channel is that the Channel Number assigned to a Part can be changed. If more than one Part is assigned the same Channel Number, then all those parts will respond to MIDI messages received on that Channel. Since each Part can play a separate instrument, the effect is multiple instruments playing the same notes. This is called layering.


To play different "instruments" on the original synthesizers, one had to physical connect different parts of the synthesizer with patch cables. Thus changing instrument became known as changing the Patch.
In Roland terms, a patch includes not only the instrument setting but the effects settings too.


Each note in a scale has a specific pitch. Playing the same note of the same scale on different instruments will produce the same pitch.

Patch Change (PC)

The Patch Change message is used to select one of one hundred and twenty-eight instruments in the current bank of the current map.
Patch Change is a channel message.

Pitch Bend

Pitch Bend messages smoothly change the pitch of all playing notes in a channel. Many MIDI devices employ a lever or wheel to control the transmission of these messages.
Pitch Bend is a channel message.

Poly (CC 127)

If the Poly MIDI message is sent to a channel, multiple, simultaneous notes can be played on that channel. This is useful for instruments that can play chords.
Poly is a channel message.
See also Mono (CC 126).

Polyphonic Key Pressure

See aftertouch.


The polyphony of a synthesizer is the maximum number of voices (or sounds) that can be played simultaneously. Some synthesizers employ more than one voice to produce a single note for some instruments. These instruments reduce the number of notes that can be played simultaneously.


Ports are used to overcome the sixteen channel limit imposed by MIDI. Each port can address sixteen channels.

Portamento (CC 5, CC 65, CC 84)

Portamento creates a sliding effect by smoothly changing pitch from the last note played to the pitch of the currently playing note.
Use control change (CC) 65 to switch portamento on or off.
Use CC 5 to control how quickly the pitch transition takes place.
Use CC 84 to specify a starting note without actually playing the note.
Portamento is a channel message.

Program Change

See Patch Change.



Registered Parameter Number (RPN) (CC 64 and CC 65)

RPN messages are used to modify three parameters: pitch bend sensitivity, master fine tuning and master coarse tuning.
The RPN messages are used to select the desired parameter and then the data entry messages are used to change the parameter.
RPN messages are defined in the standard MIDI specification and are consistent across synthesizers.
RPN messages are Channel Messages.
For examples, see the RPN and NRPN tutorial.


See envelope.

Reset All Controllers (CC 121)

The Reset All Controllers message will return all controller values to their default values.
The Reset All Controllers message is a Channel Message.


By adjusting the Resonance value, frequencies or overtones in the area of the cutoff frequency can be emphasized or de-emphasized.
Resonance can be altered with NRPN.


Reverb is an effect that emulates what would happen to a sound with different surroundings. A sound reverberates much more in a large hall than in a small room.


Scale Tuning

Scale tuning allows small adjustments to the pitch of each note in the octave. All octaves are affected equally. Scale tuning can be used to create different musical scales.


A Sequence is simply a collection of MIDI messages that can be sent to a MIDI device to produce music. A sequence is usually created and modified in a sequencer and can be saved to file like a document. These files are themselves often referred to as sequences. Most sequencers have a proprietary file format, but the most common format you will encounter is the Standard MIDI File format.
A sequence is usually divided into multiple tracks. Each track contains events, which are usually MIDI messages. A track can be assigned a port which is set to a specific MIDI device. The track is also assigned one of the sixteen MIDI channels on that device. The absolute start time of each event is represented either as Bar(Measure):Beat:Tick or as SMPTE time code.


A Sequencer is software that is used to read, edit, save and play MIDI sequences. A sequencer can be used on a computer or a dedicated hardware device connected to a MIDI device. Some MIDI devices have built-in sequencers.


See Standard MIDI File.


SMPTE stands for Society of Motion Picture and Television Engineers, and is pronounced "sempty". It is a time code developed by engineers for synchronizing audio and video. SMPTE time code is represented as hh:mm:ss:ff, which is hours:minutes:seconds:frames.

Soft (CC 67)

The Soft controller message emulates the soft pedal of a piano by lowering the cutoff frequency thus dampening the sound.
Soft is a channel message.

Sostenuto (CC 66)

The Sostenuto controller message emulates the sostenuto pedal on a piano. The result is to sustain only notes already playing.
Sostenuto is a channel message.

Standard MIDI File (SMF)

The Standard MIDI File format is a specification developed by the International MIDI Association. It is an internationally recognized method of saving a MIDI sequence to a file on disk.


See envelope.

System Exclusive Message (SysEx)

A method of two way communication between MIDI devices. It is called "exclusive" because the message is coded to address a specific MIDI device.
If MIDI devices are connected in a daisy chain, only those devices which recognize a specific SysEx message will respond to it. However, if you have more than one of the same MIDI device in the chain you would need to change the device ID to make them act like different devices.
To learn how to use SysEx messages, see the SysEx Tutorial.



Timbre is another word for sound. It is sometimes used interchangeably with patch and instrument.
Multitimbral is the term used for MIDI devices capable of playing many sounds simultaneously.

Time Variant Amplitude (TVA)

"Amplitude" in this instance means "volume". "Time variant" means "changing with time". Synthesizers use LFOs to cyclically change a sound. In this instance, it is the amplitude that is being varied to create a tremolo effect.


A track is part of a sequence. It stems from the days when multitrack tape recorders were used to record early synthesizers that could only play one patch at a time. Once one track was recorded, the synth would be repatched and while the previous tracks were played back, the new track would be recorded with the new patch.

Time Variant Filter (TVF)

A Time Variant Filter is simply a changing of the cutoff frequency over a period of time. A Low Frequency Oscillator is used to cyclically vary the cutoff frequency. The rate (speed) and depth (amount) of the variation can be controlled.



Variation (CC 0)

The Roland Sound Canvas range of synthesizers have 128 capital tones, each of which have a maximum of 127 variations. Variations are usually the same kind of instrument, but of a different type. For example "Old Upright" is a variation of the "Honky-tonk" capital tone.
Not all variations are actually used. Different maps have a different number of variations. In the SC-88 Map, some capital tones have no variations, while others have as many as thirteen.
The variation message is a Channel Message.
In Roland terminology, a variation is the same as a bank.
For more details have a look at Selecting Roland Capital Tones and Variations.


The term "velocity" in MIDI terms is misleading. Basically it is a value representing how hard a note is played on a MIDI device such as a keyboard. "Hard" implies pressure, so to avoid confusion with aftertouch, which deals with pressure, it was decided to use "velocity" which implies speed. Thus the faster (harder) a note is played, the louder it will sound.

Velocity Sensitive

Some MIDI devices, such as a keyboard, can sense how fast (hard) you play notes. This value, known as the velocity, is embedded in the Note On message. Such devices are known as "velocity sensitive" devices. The sensitivity can usually be adjusted to your playing style so that notes don't sound wildly different in volume.


Varying the pitch of a playing note very slightly, less than a trill, is known as "vibrato". It is used to make a sustained note sound more interesting.
The Roland Sound Canvas can alter the characteristics of vibrato with NRPN messages.


In synthesizer terms, a voice is usually a single, discreet sound. Synthesizers are limited in the number of voices they can play simultaneously. The maximum number of simultaneous voices a synth can play is known as its polyphony.


See level.





Please let me know if I have made any mistakes or if there are MIDI terms I have not included here.

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