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MIDI
MIDI Maestro Manual
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With INC/DEC (increase/decrease) messages which adjust the tempo up or
down by 1 BPM
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By skipping directly to a specific tempo BPM using the MSB/LSB system, like
in the Song Selection system.
However, it’s a bit more complicated because, unlike the Song Selection system
where you have dedicated CC commands to represent the MSB (CC:0) and LSB
(CC:32), there are no dedicated CC commands for Tempo.
So we use the “NRPN Register” (Non-Registered Parameter Number) which is a
general purpose MSB (CC:99) and LSB (CC:98). This can be used to control
tempo, any other parameter, or multiple parameters at once.
Currently we’re only using it to control tempo, but we follow the MIDI Standard
protocol to leave room for further control in the future. Because of this
capability for multiple parameter control, the steps below are followed.
INC/DEC (see
https://www.midi.org/specifications
Some devices require you to set the CC commands that will become the
NRPN MSB and LSB banks before using them. You do this by first pressing
CC99 with a value equal to the new Bank MSB CC command. Then by
pressing CC98 with a value equal to the new Bank LSB CC command. Please
refer to your device's manual to see if this is necessary.
For example, you first send the command CC99 value 65, now a CC65
command will activate a specific MSB layer. Then, you send a CC98 command
with a value of 66. Now, a CC66 that follows a CC65 command will select an
LSB layer.
For some systems, like the BeatBuddy’s Tempo, the amount of commands
allowed from just the MSB and LSB commands are enough to cover the range
of values the unit can use. In other cases, the unit may use a PC command
after the MSB and LSB commands to increase the value range.
NRPNs and the BeatBuddy
Since the BeatBuddy’s tempo ranges from 40BPM - 300BPM, we can’t use just
one CC command to cover the whole range because a CC command can only
have 128 values.
There are two ways of changing the tempo.
