Pi has been kicking about in modern music for a while now, even mainsteam (well, sold in HMV) artists are doing it. To celebrate Pi Day I did a bit of research on this topic. By the end of this post, not only will you have the benifit of all Google’s knowlege on the subject, you will gleam that little bit extra development by yours truly in the form of a fantastic composition of about 10 seconds length.

It all began when mon pére sent me a link to a flash application that uses pi to 10000 decimal places to generate random music. Basically, it assigns each digit 0-9 with a pitch and then runs through pi playing the notes that correspond to each number as it comes up.

The woman in this video has treated pi in the same way, but she has cleverly chosen pitches that make it sound alright, unlike the blues scale, which sounds horrible. I think having a real(ish) performer contributes to its success as well.

This idea can be extended by calculating pi in different counting systems, like binary, hexadecimal and base 12. This means one can genrate pi music for any scale or combanation of notes, rather than just restricting oneself to 10 notes (or having to use notes twice or miss two out of the chromatic scale as in the Pi10k). And yes, the idea has been used visually, assigning a colour to each digit and then using a colour a pixel to fill a pre-defined space.

In theory, as pi is an irrational number and therefore extends forever, any and every melody ever possible is contained somewhere in it. Of cource, you’d have to wait for quite a long time for Ode to Joy to turn up; personally, I think it would be worth it.

So while there is an abundance of pi-generated melody, there seems to be nothing out there that uses pi to generate the harmony or rhythm of a work. Naturally, I had to give it a go. I assigned each chord of the major scale a number, and ran through pi in base seven (3.06636514320361) playing the chords as they came up. I allowed inversions and doubling al la charales, and came up with this:

click to enlarge

More Pi Links

• Rather worryingly, there seems to be a spate of Pi Carols available to be sung on Pi Day (14th March) including my personal favourite Oh Number Pi to the tune of Oh Christmas Tree. After you’ve heard one, you’ve heard them all however.

• Now the first thing that came into my head thinking of pi was, of course, Kate Bush’s song Pi from her latest albulm Aerial

• Inevitably, pi generated music is used in hypnotherapy/mediation style musical healing if your interested.