MIDI clock is a type of MIDI message that allows multiple devices to all sync to a reference tempo.
Now that we know what MIDI clock is, let’s see how it’s useful for guitar players. MIDI clock is handy for guitarists given that it can be used to synchronize the tempo of multiple guitar pedals from a single main tempo clock source. This source can also synchronize the tempo with a DAW on a computer or with a looper pedal.
MIDI clock for guitar pedalboards
Generally, on a guitar pedalboard, when MIDI messages are sent to various guitar pedals they are sent to a specific MIDI channel from 1 through 16. Each MIDI device on the pedalboard listens to only messages from that specific channel. Devices can be set to listen on all channels, but usually they are set to listen on only one channel.
MIDI clock is different. Given it’s normally used to synchronize multiple devices, MIDI clock is usually broadcasted to all devices in the system regardless of their MIDI channel.
This allows a guitarist to tap tempo on a single location, or perhaps trigger tempo messages saved to a preset for a specific song. The main MIDI clock generator will send out this message to the devices in the system and that’s how your digital delay pedal and perhaps also your tremolo pedal know what tempo they should be oscillating at.
Some source devices send MIDI clock on a persistent basis. This means that once the midi clock is set, the device will continue sending those clock messages non-stop. Other source devices can be set so that they send MIDI clock for a brief amount of time and then stop. By then, the other devices in the system have all sync’d to the corresponding tempo and will stay this way until the master MIDI clock source sends out a different tempo.
MIDI clock can be an invaluable tool on your pedalboard
MIDI clock is one of the most useful tools on any MIDI-equipped pedalboard. That all said, it’s possible to have devices ignore the MIDI clock. For example, some guitarists do not like their modulation, such as a phaser or chorus to match their song’s tempo. For situations like this, most modern MIDI guitar pedals allow the option of setting them to ignore the global MIDI clock. This can allow you to have your delay in time with the song, but modulation be in free time.
For everything about MIDI, visit the MIDI Association.