10.6

947Logic Pro User Guide
Fader: MIDI events in the Logic Pro Environment
Each fader has an Input definition and an Output definition.
• Input definition: Determines the types of MIDI events that can remotely control the
fader.
• Output definition: Determines the types of MIDI events the fader sends out.
A fader can, therefore, convert one type of MIDI event to another. Most MIDI events consist
of three bytes:
• The first byte indicates the type and channel of the MIDI event (a note on channel 3, for
example).
• The second byte indicates the first data value (the pitch of a note event, for example).
• The third byte indicates the second data value (the velocity of a note event, for
example).
A few MIDI events—program change and aftertouch—only use two bytes. Faders and
transformers always provide for three bytes, with the second byte being discarded when
these special, 2-byte messages are received.
Fader parameters are provided for setting the message type, MIDI channel, and the first
data value. Note that the message type and MIDI channel are actually combined in the
resulting MIDI event. The second data value is determined by the fader setting, or if the
fader is being remotely MIDI-controlled, by the incoming MIDI event.
The following are used to define the Input and Output parameters:
• Output (or Input): Defines the event type.
• Channel (1 to 16): Defines the MIDI channel of the event.
• -1- (0 to 127): Defines the first data byte of the event. In some cases, such as pitch
bend, this is an actual data value. In other cases, such as MIDI controllers, this indicates
the controller type (volume, pan, and so on). In other cases, such as aftertouch, this
byte is unused.
The -1- parameter options are described here, including how the fader position affects
them (for both the Input and Output definitions):
• Note On: The -1- parameter sets the pitch, and the fader position sets the velocity.
This is most useful as an Input definition, for trapping specific notes and converting
them to other MIDI events, or simply monitoring their velocity. If you move a fader with
an Output definition set to Note On, a note off MIDI event immediately follows the note
on. This might be useful for creating onscreen drum pads from button style faders, for
example.
• P-Press: The -1- parameter sets the pitch, and the fader position sets the amount of
Poly Aftertouch (polyphonic aftertouch).
• Control: The -1- parameter sets the MIDI controller number (the controller type), and
the fader position sets the controller value. The controller type can actually be selected
by name, via the pop-up menu that appears when you click-hold the -1- parameter.
• Program Change: The -1- parameter is ignored. The fader position determines the
program number.
• C-Press: The -1- parameter is ignored. The fader position sets the channel aftertouch
(monophonic aftertouch) amount.