Specifications
Chapter 3: Pro Tools Concepts 19
You can apply Active or Inactive modes to all or
all selected tracks using standard Pro Tools mod-
ifiers (Alt and Alt+Shift in Windows, Option and
Option+Shift on the Macintosh). Side-chain in-
puts support direct active and inactive switch-
ing, but do not follow switching all or all se-
lected side-chain inputs.
MIDI Concepts
MIDI (Musical Instrument Digital Interface) is a
communication protocol for musical instru-
ments. This industry standard enables connec-
tions between a variety of devices from different
manufacturers. Examples of MIDI-compatible
equipment include synthesizers, sound mod-
ules, drum machines, patch bays, effects proces-
sors, MIDI interfaces, and sequencers.
MIDI devices are equipped with 5-pin DIN con-
nectors, labeled as either IN, OUT, or THRU.
The MIDI OUT port transmits messages; the
MIDI IN port receives messages; and, MIDI
THRU echoes whatever is received from the IN
port. MIDI devices are connected with MIDI ca-
bles that are available at most music stores.
A single MIDI cable can transmit a separate set
of messages for each of the 16 channels. These
16 channels correspond to separate MIDI de-
vices or to multiple channels within a single de-
vice (if the device is multi-timbral). Each channel
represents a discreet instrument sound; for in-
stance, bass on channel 1, piano on channel 2,
and drums on channel 10. Similar to a multi-
track tape recorder, a MIDI sequencer can record
complex arrangements—even using a single
multi-timbral keyboard.
MIDI Terms
The following are some basic MIDI terms:
MIDI Interface Hardware that lets computers
connect to and communicate with MIDI de-
vices.
MIDI Device Any keyboard, sound module, ef-
fects device or other equipment that can send or
receive MIDI information.
MIDI Controller Any MIDI device that transmits
MIDI performance data. These include key-
boards, MIDI guitar controllers, MIDI wind in-
struments, 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 Sound Source Any MIDI instrument capa-
ble of playing back MIDI-triggered sound.
Sound sources receive MIDI from their MIDI IN
ports.
MIDI signal flow
Not all devices will have all three MIDI
ports (IN, OUT and THRU).
echoed from IN