5. FAQ

On this page you can find frequently asked questions on: "MIDI interfaces".

 

Active Sensing

A MIDI event that some devices send out at regular intervals to determine whether there are any other MIDI devices connected. Some devices do not respond well to it – if you are encountering problems with MIDI communication it can be a good idea to ‘filter’ this out with your sequencer.

Aftertouch

A MIDI control function found on some keyboards that’s activated by pushing down on the keys after they have been struck initially. The function usually controls parameters such as vibrato or filter cutoff.

Bank Select

MIDI control instruction for switching between different sound banks on a MIDI sound device.

Bulk Dump

Sending or storing all of a MIDI device’s parameters. Used for backing up user data in case of power failure etc.

Device ID

If you have several devices of the same type, you can assign different Device IDs to them in order to address them independently. Normally only applicable to System Exclusive data.

Event or MIDI Event

The pressing of a key, the releasing of a key, the velocity of the stroke, the changing of volume etc – all of these things are individual MIDI events, as are any other commands sent over MIDI.

General MIDI (GM)

A standard which regulates the allocation of sounds and MIDI controller numbers. GM specifies 128 of the most frequently used sounds as well as controller numbers for effects and patch changes. The idea is that any MIDI file (a set of MIDI song data) that conforms to the GM standard will sound correct when played through any GM compatible device.

Local On/Off

Switches off the connection between a MIDI synthesiser’s keyboard and the sound generating engine of the same device. Local On enables the keyboard to play its own sounds, whereas with Local Off, the keyboard only sends MIDI out of the instrument’s MIDI Out port. This enables a keyboard to play other sound modules or software instruments without playing its own sounds at the same time.

MIDI Cable

A 5 pin cable up to 25 meters long for connecting between MIDI devices – MIDI amplifiers are available if you need a longer cable run that this.

MIDI Channel

The MIDI standard dictates 16 different channels, over which different sounds and/or MIDI devices can be accessed independently. In order to be able to use a certain channel, the respective MIDI controller (e.g. keyboard or sequencer) must use the same channel as the sound module.

MIDI Clock

A regular MIDI event used in conjunction with MIDI Song Pointers to provide synchronisation between MIDI devices. Typically used between two tempo-dependent devices such as a sequencer and a drum machine. Now largely superseded by the more flexible MIDI Time Code (MTC).

MIDI Filter

Removes unwanted MIDI events. This is often used to block events from reaching a sound module when using a number of devices in a chain, such as patch changes or pitch bend. Alternatively it is used by sequencers simply to filter the display of information, rather than the actual events themselves.

MIDI In

Port through which MIDI data is received.

MIDI Merge

Describes the combining of MIDI information from two or more sources into a single MIDI connection. For instance if you wanted to play a sound module from a keyboard and a MIDI drum pad simultaneously (perhaps on different channels), you could plug both of them into a MIDI Merge box, and then plug the box’s output into the sound module’s MIDI In port. As this involves merging data, it cannot be done simply by joining two cables together!

MIDI Out

Port through which MIDI data is transmitted.

MIDI Thru

Port that mirrors the MIDI In in order to route MIDI data in a chain to a second device.

MIDI Time Code (MTC)

A regular clock signal that improves over MIDI Clock by stamping each event with an absolute time, thereby allowing devices to be restarted anywhere in a song and immediately synchronise.

Panic

A function that clears all sounding notes by sending out a ‘note off’ command for every possible MIDI note on all channels.

Program Change (Patch Change)

The standard MIDI instruction for changing a sound.

Sequencer

A piece of hardware or software for the recording, editing and playback of MIDI information.

System Exclusive (SysEx)

MIDI data that is only understood by one particular model of MIDI device. Often used for transferring patch information via ‘Bulk Dumps’.

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