DigiDesign Pro Tools, Reference Manual, Page: 27 / 886

Chapter 2: Pro Tools Concepts 13
The MIDI protocol provides 16 channels of
MIDI per port. A single MIDI cable can transmit
a separate set of messages for each of the 16
channels. These 16 channels can correspond to
separate MIDI devices or to multiple channels
within a single device (if the device is
multi-
timbral ). Each channel can control a different
instrument sound. For example, bass on
channel 1, piano on channel 2, and drums on
channel 10. Similar to a multitrack tape re-
corder, a MIDI sequencer can record complex ar-
rangements—even using only a single multi-
timbral keyboard.
MIDI Terms
The following are some basic MIDI terms:
MIDI Instrument
A hardware MIDI device or soft-
ware instrument (such as an instrument plug-
in).
MIDI Interface
Hardware that lets computers
connect to and communicate with MIDI de-
vices.
MIDI Device
Any physical MIDI keyboard,
sound module, effects device, or other equip-
ment that can send or receive MIDI informa-
tion.
MIDI Controller
Any MIDI device that transmits
MIDI performance data. These include MIDI
keyboards, MIDI guitar controllers, MIDI wind
controllers, and others. Controllers transmit
MIDI from their MIDI OUT ports.
MIDI Control Surface
Any device (such as the
Digidesign Command|8), which uses a MIDI
connection to send control messages to a soft-
ware program, but is not generally used to
record MIDI information.
MIDI Tone Generator (MIDI Sound Source) Any
MIDI device capable of playing back MIDI-trig-
gered sound. Sound sources receive MIDI from
their MIDI IN ports and output audio from their
audio outputs.
Multitimbral The ability of one MIDI device to
play several different instrument sounds (such
as piano, bass, and drums) simultaneously on
separate MIDI channels. This makes it possible
for a single multi-timbral MIDI instrument to
play back entire arrangements.
MIDI Channel Up to 16 channels of MIDI perfor-
mance data can be transmitted on a single MIDI
cable. The channel number separates the differ-
ent messages so your sound sources can receive
the right ones.
Program Change Event A MIDI command that
tells a sound source which of its sounds (or
sound patches) to use. The MIDI protocol lets
you choose from a range of 128 patches.
Bank Select Message Many devices have more
than 128 patches, which are arranged in banks.
The Bank Select Message is a MIDI command
that specifies the bank of patches from which to
choose.
Local Control A controller setting found on most
MIDI keyboards that lets them play their own
sound source. Disabling “local control” ensures
that a device’s internal sound source is only
played by external MIDI messages (such as those
sent from Pro Tools when MIDI in Pro Tools is
routed to the MIDI keyboard). When using
Pro Tools, “local control” should usually be dis-
abled. When “local control” is off, your key-
board still transmits data to its MIDI OUT port.
Continuous Controller Events MIDI instructions
that allow real-time changes to notes that are
currently sounding. These include pitch bend,
modulation, volume, pan, and many others.