Midi Messages In-Depth; Program & Bank Changes - M-Audio KeyStudio 25 User Manual

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Session KeyStudio 25 User Guide
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MIDI Messages In-Depth

Program & Bank Changes
When the MIDI standard was first established,
it enabled the user to access only 128 different
sounds using program change messages (0-127).
As MIDI devices grew to be more sophisticated
and contain more sounds, bank change messages
were included in an updated MIDI specification to
allow for more than 128 sounds to be accessed.
The language MIDI uses to communicate between
musical instruments only allows for program
change commands 0-127, for a total of 128
possible programs (127 programs + program
"0" = 128 programs total). Because of inherent
limitations of the MIDI communication protocol,
the number of directly accessible programs
(using program change messages) cannot easily
be expanded beyond 128. Thus, a system of
banks, with 128 sounds in each, has been created
that enables manufacturers to overcome the
128-sound MIDI limit.
128 Banks with 128 sounds in each bank is the
basic principle used to expand the number of
accessible sounds. However, to avoid reaching the
new limit of the resulting 16,384 possible sounds
(128 banks x 128 programs) accessible using a
bank change combined with a program change,
another layer of banks was added. The result is a
system of 128 banks that can contain 128 sub-
banks in each of them, which, in turn, can contain
128 sounds (programs) within them.Bank change
messages are useful when calling up sounds from
a large library that may exist in a particular sound
module or software synth. For example devices
that are built with Roland's GS specification or
Yamaha's XG specification require you to specify
a bank change in order to access the extra voices
and effects that these devices provide.
MIDI CC 0 is the bank select MSB (Most Significant
Byte) message. This MIDI message is 7-bit in size
and can be used to select any of 128 banks. This
message can be used in conjunction with MIDI
CC 32 which is bank select LSB (Least Significant Byte): a separate 7-bit message allowing additional selection of any of another 128
sub-banks. The combination of Bank MSB and LSB messages gives a 14-bit message that can select any of a possible 16,384 banks.
Each bank can in turn contain 128 possible sounds selected via a separate program change MIDI message. This enables a user to
theoretically recall over two million programs directly, using only MIDI commands. However, most devices only use a few different
banks, and allow you to access them with either a Bank LSB message or a Bank MSB message. Please consult your synthesizer's or
software's documentation for more information on which type of bank change messages they can process. "