How does MIDI pitch bend work?
Pitch bend is its own MIDI message, not a Control Change. It carries one value from 0 to 16383: 8192 means no bend, 0 is fully down and 16383 is fully up. The message says how far the wheel has moved, not how many semitones to bend. The sound that receives it decides the distance, and the usual default is two semitones in each direction.
I make InputConfig, a free Mac app that reads pitch wheels and sends pitch bend from a game controller stick, which is the last section.
Steps
- Move the pitch wheel and watch the value in a MIDI monitor: it rests at the center and returns there when released.
- Set the bend range on the receiving instrument, in semitones.
- If the pitch does not return to normal, check that the wheel's resting value is the center.
Read the message
| Part | Value | Meaning |
|---|---|---|
| Status byte | 0xE0 to 0xEF | Pitch Bend, on channel 1 to 16 |
| First data byte | 0 to 127 | The fine half of the value |
| Second data byte | 0 to 127 | The coarse half of the value |
The two halves join into one 14-bit number. Pitch bend has 16,384 steps where a Control Change has 128, which is why a bend sounds smooth.
InputConfig is free on the Mac App Store. macOS 14 or later, no account, no tracking, open source.
Know the values
| Value | Also written | Meaning |
|---|---|---|
| 0 | -8192 | Full bend down |
| 8192 | 0 | Center, no bend |
| 16383 | +8191 | Full bend up |
Some tools show the raw value from 0 to 16383, and others subtract 8192 and show it from -8192 to 8191. A wheel at rest should read exactly the center. The MIDI tester shows the lowest and highest value a wheel reaches, and a wheel that rests off center drifts like a worn stick.
Set the bend range on the receiving end
The message carries a position, and the instrument turns that into pitch. With a range of two semitones, full up is two semitones sharp. With twelve, the same wheel movement is an octave. Most instruments have a pitch bend range setting, and General MIDI devices default to two semitones.
If the wheel bends too far or not far enough, change the range on the instrument, not on the keyboard.
Tell it apart from the mod wheel
The two wheels on a keyboard send different kinds of message. The pitch wheel springs back to the center and sends Pitch Bend. The modulation wheel stays where you leave it and sends CC 1, with 128 steps. There is no CC number for pitch bend, because it is not a CC. The MIDI CC list covers the mod wheel and the rest.
Bend from a game controller stick
A stick springs to center like a pitch wheel, which makes it a natural bend control. In InputConfig, bind a stick axis to Pitch Bend and the bend follows the stick. From a button, it bends fully up while held and returns to center on release. Going the other way, a keyboard's pitch wheel can be an input: it binds in plus and minus, like a stick axis, so pushing it up and pulling it down can do two different jobs on the Mac. A thumbstick gives a controller the one thing its buttons lack: a bend. MIDI output has the setup.
The short version
- The message. Status 0xE0 plus the channel, then two data bytes that make one number.
- The values. 0 down, 8192 center, 16383 up.
- The distance. Set on the receiving instrument, usually two semitones.
The wheel sends a position, and the instrument decides what it means.
Questions
What is the MIDI CC number for pitch bend?
There is none. Pitch bend is a separate message with its own status byte, 0xE0 plus the channel, and a 14-bit value. The modulation wheel next to it is CC 1.
What are the MIDI pitch bend values?
0 to 16383. The center, no bend, is 8192. Some tools show the same range as -8192 to 8191 with 0 at the center.
What is the default pitch bend range?
Two semitones up and two down on General MIDI devices. Most instruments let you change the range in their own settings.
Why is my pitch stuck sharp or flat?
The instrument last received a pitch bend value that was not the center. Move the wheel and let it spring back, or send a centered value. A wheel that rests off center needs cleaning or repair.
Is pitch bend 7-bit or 14-bit?
14-bit. It uses two data bytes that combine into one value with 16,384 steps.
Related
Free. macOS 14 or later. No account, nothing leaves your Mac. Open source on GitHub.
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