Sonic Pi Chord Cheat

# Create Chords in Sonic Pi, to send via MIDI to your other DAW or synth
# See https://www.youtube.com/watch?v=qd8SEL_rTNw

define :chordSeq do | tonic, mode, degs |
  majorKeyTriads = [:M,:m,:m,:M,:M,:m,:dim]
  minorKeyTriads = [:m,:dim,:M,:m,:m,:M,:M]
  majorKey7s = [:M7,:m7,:m7,:M7,:dom7,:m7,:halfdiminished]
  minorKey7s = [:m7,:halfdiminished,:M7,:m7,:m7,:M7,:dom7]
  
  cs = []
  
  degs.each { | deg |
    case deg
    when 1..7
      root = degree(deg,tonic,mode)
      lookup = (mode == "major") ? majorKeyTriads : minorKeyTriads
    when 71..77
      deg = deg - 70
      root = degree(deg,tonic,mode)
      lookup = (mode == "major") ? majorKey7s : minorKey7s
    end
    theChord = chord(root,lookup[deg-1])
    cs.append [tonic,mode,theChord]
  }
  cs
end

use_bpm 120

live_loop :piano do
  cs = chordSeq(:C3,"minor",[1,76,4,75, 5,7,74,5,
                             1,76,4,75, 5,7,74,1])
  cs.each {| xs |
    tonic,mode,c = xs
    
    c.each {|cn| midi_note_on cn, 60,
    port: "loopbe_internal_midi_1" }
    sleep 2
    c.each {|cn| midi_note_off cn,
    port: "loopbe_internal_midi_1"}
    
    
    midi scale(tonic,mode).choose+24, 60,
    port: "loopbe_internal_midi_1"
    sleep 1
    
    midi scale(tonic,mode).choose+24, 60,
    port: "loopbe_internal_midi_1"
    
    sleep 1
  }
end