Sonic Pi

THX_logo.rb

##################
# THX logo sound #
##################

# THX revealed their sound logo here: https://twitter.com/THX/status/1000077588415447040/photo/1

# beginning random notes in the 200-400Hz

# you can play around with how many intervels you want in the
# 200 to 400hz range, I found 20 to be nice
interval = 10

# hz_to_midi() conveniently converts hz to midi notes
# so you can make a range() and pick a random Hz to convert to midi
random_notes = [
  hz_to_midi(range(200, 400, steps: interval).choose),
  hz_to_midi(range(200, 400, steps: interval).choose),
  hz_to_midi(range(200, 400, steps: interval).choose),
  hz_to_midi(range(200, 400, steps: interval).choose),
  hz_to_midi(range(200, 400, steps: interval).choose),
  hz_to_midi(range(200, 400, steps: interval).choose),
  hz_to_midi(range(200, 400, steps: interval).choose),
  hz_to_midi(range(200, 400, steps: interval).choose),
  hz_to_midi(range(200, 400, steps: interval).choose),
  hz_to_midi(range(200, 400, steps: interval).choose),
  hz_to_midi(range(200, 400, steps: interval).choose)
]

# these are the target notes for the final chord
thx_chords = [:d1, :d2, :a2, :d3, :a3, :d4, :a4, :d5, :a5, :d6, :fs6]

# you can play with how long you want notes to sustain
# overlapping decaying notes can sound very cool!
sustain_amt = 8

# storing a synth allows us to play it and control its parameters
# we are trying to control the note_slide because this will transform
# the intial random notes to the target THX sound notes
thx = synth :saw, amp: 1.5, notes: random_notes, note_slide: sustain_amt,
  sustain: sustain_amt + 4, cutoff: 40, cutoff_slide: sustain_amt,
  attack: 0.05, release: sustain_amt / 2

# finally use control to map the notes from thx (random initial notes) to the thx_chords (final destination)
# move cutoff from 40-120 as well so we ease in
control thx, notes: thx_chords, cutoff: 120