Thank you this helps -- the "Music Genome Project" was part of this fork & schism. Pandora says little about it[0], and the open portions[1] were last updated in 2014.
At least someone's still at it, and all this helps me find my notes from that time.
https://github.com/LDugar/MusicGenome/raw/master/Decoding-th...
[0]http://www.pandora.com/about/mgp [1]https://github.com/omgDB
[1] https://en.wikipedia.org/wiki/Music_Genome_Project