MIDI with Sonic Pi on OSX

README.md

Warning

These instructions are mainly for my own personal reference and should not be considered a supported feature of Sonic Pi. For experimentation only. Assumes OSX 10.10

1. Setup a virtual midi channel on OSX

This is sometimes referred to as a "loopback" device and it should allow the various software applications to communicate.

• Open /Applications/Utilities/Audio\ MIDI\ Setup.app/ and go to "Window > Show MIDI studio".
• Double click IAC Driver
• In the new window, click Device is online
• Close Audio MIDI Setup

2. Download MIDI Monitor

This is just to watch the messages fly around the system. Not essential for this.

3. Download Virtual MIDI Piano Keyboard (VMPK)

• Copy to the Applications folder
• Open and go to "Edit > MIDI Connections"
• Enable MIDI input, select CoreMIDI as the driver and IAC Driver Bus 1 as the "Input MIDI Connection". The outputs should both be FluidSynth.

4. Open Sonic Pi and run the following:

require 'unimidi'

output = UniMIDI::Output.open(:first)
notes = [36, 40, 43, 48, 52, 55, 60, 64, 67] # C E G arpeggios
duration = 0.2

output.open do |output|

  8.times do
    note = (scale :a1, :minor_pentatonic).choose
    output.puts(0x90, note, 100) # note on message
    sleep(duration)  # wait
    output.puts(0x80, note, 100) # note off message
  end

end