How is pitch bend data transmitted and interpreted by a MIDI synth?
A Pitch bend message is encoded with two 7-bit data bytes (as per the MIDI spec). All MIDI data bytes have a range of 0 thru 127. The MIDI status bytes all have values between 128 and 255, so it is illegal to send data bytes bigger than 127, or they will be misinterpreted as status bytes (note on, note off, controller, etc). So if you want to encode values bigger than 127, the MIDI spec uses two or more data bytes. Pitch Bend uses two data bytes. The 7 bits of the MSB (most significant byte) and the 7 bits of the LSB (least significant byte) are combined to make a 14 bit possible range of values. Fourteen bytes can count from 0 thru 16383. A Pitch Bend of zero is considered to be halfway up in that range, so most software subtracts 8192 from the ‘true 14 bit value’ to display the pitch end value. That’s why most programs, including Band-in-a-Box and PowerTrack Pro Audio, display the pitch bend range -8192 thru +8191. There is a pitch bend range controller message that tells a synth how
