The timing of this golden-era demos set is perfect, as CSN’s shadow looms large over a new school of harmony-drunk indie rockers. Unfortunately, the song selection of this set of 1968-71 rarities is a mixed bag, and most are solo performances lacking the group’s magical interplay. One exception is a sprightly “Marrakesh Express,” with David Crosby and Graham Nash melding voices. Several familiar tunes get skeletal readings, including Nash’s piano-only “Chicago,” Stephen Stills’ “Love the One You’re With” and a slow-mo “Déjà Vu,” with Crosby scatting on the outro. Nice footnotes all, but no substitute for the originals.