The ever increasing paradox with three tritone pairs

I used Sonic pi to implement the tritone paradox in Sonic PI.

Tritone paradox

This is the paradox where 2 tones played at the same time and separated by half an octave seem to be ascending to some listeners and descending to others.

Some people question the seemingly infinite rise or descent.

Process

Like many things around us, we can translate this illusion by a process.

A collection of notes keeps on rising in pitch
When a given note reaches some (high) frequency, it goes down a multiple of 1 octave

Implementation

We use a sinusoidal wave sound, it’s the purest in the frequency space.
We instantiate six pitches spanning three octaves.
We play them with a high sustain and decay.
In a loop:
- increment the pitches by a small value (for the “sliding” effect )
- apply the pitches to notes
- cater for the edge cases (e.g. the pitches became too high)
- sleep for a short time

Thoughts

additional sounds can be inputed.
A cleaner code can be written.
some variation of this effect can be used

Code

use_synth :sine

my three notes

s=36
tritone_s=42
j=48
tritone_j=54
i=60
tritone_i=66
sustain =100

start the notes

note1=play s, attack: 0.05, decay: 50, sustain: sustain
note2=play j, attack: 0.05, decay: 50, sustain: sustain
note3=play i, attack: 0.05, decay: 50, sustain: sustain

play tritones

tritone_1 =play tritone_s, attack: 0.05, decay: 50, sustain: sustain
tritone_2 =play tritone_j, attack: 0.05, decay: 50, sustain: sustain
tritone_3 =play tritone_i, attack: 0.05, decay: 50, sustain: sustain

sleep time

m=0.225

increment

increment=0.125

live_loop :shift do
### we calculate by how much the given note is shifted
s+=increment
tritone_s+=increment
j+=increment
tritone_j+=increment
i+=increment
tritone_i+=increment

### we a pply te shift
control note1, note: s
control tritone_1, note: tritone_s

control note2, note: j
control tritone_2, note: tritone_j

control note3, note: i
control tritone_3, note: tritone_i

## never forget to sleep
sleep m
### we set boundaries
if s>72
s=24
end
if j>72
j=24
end
if i> 72
i=24
end
if tritone_s> 78
tritone_s=30
end
if tritone_j> 78
tritone_j=30
end
if tritone_i> 78
tritone_i=30
end

end