Chime in if you have more suggestions …

All music © 2020 Chris Culy

Awhile back as I was on one of my walks I heard some wind chimes. That led me to wonder whether I could simulate the sounds of wind chimes. As I worked on the million arbitrary digits from an image, I had the idea of using those digits as the “wind” to select the notes.

Many wind chimes use the notes of a pentatonic scale, so I started there. Here’s an example using the notes C D E G A.


1. Arbitrime No. 881152 in C D E G A


I’ve tried different sounds for the chimes, but I mostly prefer the vibraphone as a reasonable approximation of larger, deeper sounding wind chimes. [See the technical note below for more information on how the sound file is created.] The names of the sound files here use the name of the project: Arbitrimes (=arbitrary + chime). In addition, the number in the title indicates which of the arbitrary million digits is the starting point.

If you read that Wikipedia page, you’ll find that there are lots of pentatonic scales, each one sounding a bit different. Here are two more.


2. Arbitrime No. 761363 in C D F G A


3. Arbitrime No. 835175 in C D E♭ G B♭


That day I was walking around, the house actually had a couple wind chimes, so of course I had to be able to simulate that as well. This next example starts with the arbitrime in (2) and adds a second one.


4. Arbitrime No. 761363: 568541 in C D F G A


There aren’t many times in the example in (4) where you can hear both arbitrimes separately. But when we add more arbitrimes we can. The example in (5) adds two more arbitrimes to (4). (More than four arbitrimes becomes very muddied.)


5. Arbitrime No. 761363-568541-862412-809906 in C D F G A


All of the examples so far have used just a simple pentatonic scale. However, there’s no reason we have to limit ourselves either to a scale or to just 5 notes. The next arbitrime uses the notes of a pentatonic scale, but doesn’t arrange them in order, and includes a duplicate G. I’ve also set the tempo to be slower, more of a light breeze than a wind.


6. Arbitrime No. 23083-226204-290565 in G B♭c G D F


Instead of selecting notes manually, I’ve also tried taking notes from the melody of a song. For example, here’s one based on the beginning of Noël Nouvelet (= Sing We Now of Christmas).


7. Arbitrime No. 353988 in D A B G A F “Noël nouvelet”


Even though I’m not sure I’d consider arbitrimes music, I find them (and intended them to be) aesthetically pleasing. I hope you do as well.

I’ll leave you with 2 longer arbitrimes. The first one is an elaboration of (7) and the second one returns to the basics and uses a pentatonic scale with the octave added.


8. Arbitrime No. 353988-889800-204968-587173 in D A B G A F “Noël nouvelet”


9. Arbitrime No. 961189-13933-167553 in C E♭ F G B♭ c


Technical note

The Arbitrimes algorithm uses two pairs of arbitrary digits at a time. The first pair are used to select the note values in the current run, while the second pair determines the number and duration of the notes in the run. The starting position for the aribtrary numbers used for the note values is determined randomly, not arbitrarily.

The Arbitrimes algorithm generates abc music notation, and I use the wonderful abcjs library to create the sound files. I also used the free Convertio site to convert the 2 longer files from wav to mp3 format.