A spotty but basically worthwhile three-disc set, Collectables' 1966-1967 Unreleased Masters Collection scours the International Artists vault for previously unreleased songs, alternate takes, rehearsals, and demos of songs that appeared on The Psychedelic Sounds of the 13th Floor Elevators and Easter Everywhere, and a couple of live cuts for good measure. Its excessive length, coupled with the often-iffy sound and performance quality, makes it hard going for all but the most devout Roky Erickson fanatics; it's definitely best to be sampled no more than a disc at a time, and even then, judicious use of the forward skip button helps a lot. Most of the alternate takes sound pretty similar to the official releases, and the rehearsals are as shambolic as one would expect, especially the three falling-apart attempts at an early blues-based version of what would eventually be released as the faster, punkier "She's Got Levitation." On the positive side, the demos often feature interesting early drafts of the lyrics, and the fairly straightforward versions of folk-rock standards like "Chimes of Freedom" and "The Lonesome Death of Hattie Carroll" show where the band was originally coming from. This set is strictly for the hardcore, but it's much better than most of the collections of Erickson ephemera out there.