Sonic Pi Scripts

4 Bar Chord Progression Generator Tool

A tool for generating a 4 bar chord progression. To push the code further, change the seed, key, and scale values to generate new chord progressions. The generator is setup to create 7th chord progressions but can be modified to produce any chord.

What it sounds like:

Code:

# 4 bar chord progression generator
#  function that takes key and scale and seed as parameters
define :chord_progression do |key, scale, seed|
  # Use the scale function to get the notes of the scale
  notes = scale(key, scale)
  # Define an array of possible chord degrees
  degrees = [1, 2, 3, 4, 5, 6, 7]
  # Shuffle the degrees and take the first four
  use_random_seed 9 # Replace with any integer to generate new progressions.
  progression = degrees.shuffle.take(4)
  # Define an empty array to store the chords
  chords_array = []
  # Loop through the progression
  progression.each do |degree|
    # Get the root note of the chord based on the degree
    root = notes[degree - 1]
    # Use a case statement to determine the chord quality based on the degree
    case degree
    when 1, 4 # Major 
      quality = :major7
    when 2, 3, 6 # Minor 
      quality = :m7
    when 5
      quality = :dom7
    when 7 # Diminished 
      quality = :dim7
    end
    # Use the chord function to get the diatonic chord
    current_chord = chord(root, quality)
    # Append the chord to the chords array
    chords_array.append(current_chord)
  end
  # Return the chords array
  use_synth :dtri
  chords_array.each do |current_chord|
    play_chord current_chord, release:4
    sleep 4
  end
end

# Example usage: generate a diatonic chord progression
live_loop :prog do
  chord_progression :c, :major, 75
end

##| drumset######################
kick =  [1,1,0,0,1,0,1,0,1,0,0,0,1,1,1,1]
snare = [0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0]
hat =   [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1]

live_loop :kick do
  16.times do |hit|
    sample :bd_klub, hpf:30 if kick[hit] == 1
    sleep 0.25
  end
end

live_loop :Snare do
  16.times do |hit|
    sample :drum_snare_hard, amp:rrand(0.6,0.9) if snare[hit] == 1
    sleep 0.25
  end
end

live_loop :hat do
  16.times do |hit|
    sample :drum_cymbal_closed,  release:0.3, amp: rrand(0.05, 0.3), pan: rrand(-1,1) if spread(13,16).tick
    sleep 0.25
  end
end