So, that's pretty much it. I use iTunes to organize my music for my DJ software (Serato 1.7.8), which uses it's playlists. And there's lots of playlists/subgenres, but the most important one is the "master" Drum & Bass list, which contains every tune of this genre that I could conceivably want to throw in a set. I use this to back up my tunes of this genre to backup hard drives, USB sticks, etc. where it gets analyzed by other programs. I was so long messing around with basic functionality and Logic Pro X that I've just now discovered I can't drag all songs from this playlist to, say a USB drive and use OSX to avoid duplication...skip copying duplicates, apply to all, etc. Thought I was good to go, but I'm now rolling the DJing laptop back to Yosemite 10.10.4. *snif* I do like El Capitan more, but needs must. I tried disabling SIP, running Onyx, and I threw a couple of keyboard commands (holding option, then trying control) at it, as that was necessary to throw away an OS X program even after disabling SIP. Not sure whether they f****d it up on purpose, or by accident, but I hope it's the latter and they fix it. Total. Deal. Breaker.