Long ago, oh, say the mid-1980’s, when many of my friends had gotten computers, I resisted... “Oh, no, I get enough of computers at work, besides, what would I do with one?”  Then my buddies John and Chuck Dougherty invited me to work on the Commodore-64 version of their game, Legacy of the Ancients.  I agreed, which meant, of course, I’d have to break down and get a computer.

I did mostly sound and music on the game, so I got pretty familiar with the C-64‘s Sound Interface Device (SID) chip.  The SID chip was essentially a three voice synthesizer, with complete computer control - admittedly a science and music boy’s dream. Eventually I started playing with perfect harmonies, tuned closer to perfect ratios than our common, western, equal-tempered scale.  That in turn led to a number of programs that “played” various drones, some on the SID chip, others via MIDI on synthesizers. 

The programs evolved over time and later could change key and take advantage of the wide range of sounds on various synthesizers, but I always had a fondness for these early versions.

This recording was pulled from a cassette (shown), and is the  first of a half dozen or so experiments using different variations of the control program.  The program used the concept of tension, which increases and decreases at different rates and to different levels.   The choice of note, and the rate of change were both tied to the tension variable which makes the result a constrained randomness, which is generally more interesting than simple randomness.

The tuning is based on perfect ratios - I believe this uses a 7-limit scale, which keeps the harmonies fairly pure.  (I’ve got more about tuning here.) 

However, the tunings are not completely perfect, I added a small offset to each voice to keep them sounding distinct.   That sound was then mixed into an old analog delay to add echo and pitch shift and generally blur things up a bit.

The program used here doesn’t change key, and one could argue it is simply voicing different notes of the same, somewhat complex, chord.  Yet, I find it occasionally relaxing and sometimes easy to work to.

This one runs about 16 minutes, but you’ll have heard most of what it can do in the first couple.