Sonic Pi script creating a countermelody through contrary motion.

poster_synthdrome.rb

use_real_time # Preventing latency
use_tuning :just, :c # Just Intonation
delta=counter=naute=idx=0
previous=60
gamme=(scale 50, :minor_pentatonic, num_octaves: 5)
counter_gamme=(scale 38, :minor_pentatonic, num_octaves: 2)

with_fx :compressor, threshold: 0.1 do # Preventing clipping
  with_fx :reverb do # Everything on the same reverb
    with_fx :lpf, cutoff_slide: 0.02 do |filtre|
      melody = synth :tb303, pulse_width: 0.1, wave: 1, note: 0, release: 1000, amp: 0, note_slide_shape: 3
      counter_melody = synth :fm, divider: 4, note: 0, release: 1000, amp: 0
      live_loop :notes do
        note_on, velocity = sync "/midi/USB_Midi_Cable/4/1/note_on" # Incoming notes from Yamaha WX-11 wind controller
        if velocity > 0 # Only use actual note-ons
          delta=note_on - previous
          if gamme.index(note_on)
            idx=gamme.index(note_on)
            control melody, note_slide: 0
          else
            control melody, note_slide: 0.25
            if delta > 0
              idx=idx+1
            else
              idx=idx-1
            end
          end
          naute=gamme[idx]
          
          control melody, note: naute, amp: velocity / 127.0 # Incoming note
          if delta < 0
            counter=counter_gamme.tick
          else
            counter=counter_gamme.reverse.tick
          end
          control counter_melody, note: counter, amp: velocity / 127.0 # Incoming note
          previous=naute
        end
      end
      live_loop :windy do # Use the incoming breath control, MIDI CC#2, to modulate the low-pass filter
        control_change, breath = sync "/midi/USB_Midi_Cable/4/1/control_change"
        if control_change==2
          control filtre, cutoff: breath
        end
      end
    end
  end
end