Main Content

Arduino MIDI Rhythm Section Sequencer

Having a good software drum machine is easy and cheap today but using a mouse kills the fun for me. This is why I realized what initially was intended as a pure 64 steps hardware MIDI drum sequencer capable of triggering up to 12 different drum elements (parts), but then evolved in a rhythm section sequencer…
… there we go!

This hardware cannot generate sounds on its own, but only sequence external hardware via MIDI. This means you will need a sound generator of your drum sounds (a sampler or a drum synthesizer or whatever you prefer) capable of being triggered by MIDI note-on messages.

It’s mainly composed by a 4 x 4 buttons matrix (with LEDs), one for each step of a bar. The whole 64 steps sequence is made up by 16 steps multiplied 4 bars. Each step is 1/16th of a note.

There are two modes of operation: live mode and edit mode.

In edit mode you can actually step-by-step edit your sequence by defineing which drum will play in each step.

Your sound generator external hardware instrument (“drum”) is triggered by sending a MIDI “note on” message for different “MIDI note numbers” on channel number “10”. By default these note numbers are

drum #1 (i.e. kick) -> MIDI note number “60”

drum #2 (i.e. snare) -> MIDI note number “62”

drum #3 (i.e. clap) -> MIDI note number “64”

drum #4 (i.e. Hihat) -> MIDI note number “65”

drum #5 -> MIDI note number “67”

drum #6 -> MIDI note number “69”

drum #7 -> MIDI note number “71”

drum #8 -> MIDI note number “72”

drum #9 -> MIDI note number “74”

drum #10 -> MIDI note number “76”

drum #11 -> MIDI note number “77”

drum #12 -> MIDI note number “79”

You can change these values (and the MIDI channel) in the sketch if you prefer.

In live mode by pressing step buttons you can live play drums associated to each step by sending MIDI messages through serial. You can live record your button presses and/or incoming MIDI messages.

Both in live mode and edit mode you can mute (or unmute) a drum, “roll play” the currently active drum and “swing” your sequence.

Pitch? What’s that?

Most of drum sequencers are purely MIDI drum parts triggerers, with a fixed MIDI note number for each drum sound. In this case, we have a “rhythm section sequencer” more than a pure “drum sequencer” because you can even sequence synthesizers, within just under 3 octaves.”

Link to article

Related Content