I've just seen the following video
and I wondered how hard it was to automatically generate this myself only with software. Turns out, it is super easy.
Python
You have to install MIDIUtil:
$ sudo pip install MIDIUtil
and then you can execute the following code:
#!/usr/bin/env python
from midiutil.MidiFile import MIDIFile
# Just an example
try:
# import version included with old SymPy
from sympy.mpmath import mp
except ImportError:
# import newer version
from mpmath import mp
mp.dps = 1000 # set number of digits
# Create the MIDIFile Object with 1 track
MyMIDI = MIDIFile(1)
track = 0
channel = 0
pitch = 60
time = 0
duration = 1
volume = 100
for digit in str(mp.pi):
if digit == ".":
continue
MyMIDI.addNote(track, channel, pitch + int(digit), time, duration, volume)
time += 1
if time == 180:
break
# And write it to disk.
binfile = open("output.mid", "wb")
MyMIDI.writeFile(binfile)
binfile.close()
This will make the first 180 digits of $\pi$ to a MIDI file.
See MIDIUtil docs for more information.
Create MP3
I use timidity to create a .wav and then lame to convert it to mp3:
$ timidity -Ow -o output.wav output.mid
$ lame output.wav pi.mp3
For YouTube, I had to convert it to avi:
$ ffmpeg -loop 1 -r 1 -i pi.jpg -i pi.mp3 -c:a copy -shortest pi.avi
Examples
$\pi$:
It sounds much more intersting if you play two versions of it simultaneously, starting at different points:
$e$:
$\sqrt{2}$
Ideas
You could reserve one digit for meta-choices, e.g. making 0 a control character. If 0 is followed by...
- ... 0, all modifiers are reset
- ... 1, the pitch is doubled all the time
- ... 2, the pitch is doubled for 10 notes
- ... 3, `time = time - 5.5`
- ... 4, `tempo = tempo*2`
- ... 5, `tempo = tempo*4
- ... 6, `tempo = tempo - 10
- ... 7, volume increases in as many beats as the next two digits indicate
- ... 8, volume decreases by 10 in the next 2 seconds
- ... 9, duration is doubled
Let me know if you made something that sounds interesting 🙂