Michael Praetorius Ein Kindelein so löbelich for Sonic Pi

Felt the urge for some more early music. This piece by Michael Praetorius (1571-1621) in 8 parts lends itself very well to Sonic Pi. The parts are arranged in two groups of four, and I’ve allocated them appropriately across the stereo spectrum. I used :sine synth for the top two parts in each four and :tri for the others. I reduced the volume of the second four parts so it give an answering echo effect. Overall some reverb was applied. This version is played to pitch, but I tried it down a third (transpose -4) as well as the sine synth can be a bit piercing on the top notes.
You can get the code from https://gist.github.com/rbnpi/206a239f7244769b7e0459c63fbb084d
The code was converted from a mid file using a processing script here
You can hear the piece below