This is a simple concept that I am really glad worked out. The last couple days I have done sounds that I was simply not happy with, and I only have a certain chunk of time to work on this each day so I was pretty much out of luck. Here I used supercolider to basically make sine waves (the simplest sound possible) I start with each one at a totally random pitch, and over 2 minutes they slowly drift from that random pitch to a place in a just tuned chord.

Simple, but effective.

Here's the wav file.