This 60-song anthology of all the previously unreleased studio material from latter-day Dead reissues and box sets is as illuminating as it is exhaustive. Early tracks like "You Don't Have to Ask" spotlight the band's garage-rock beginnings, complete with Pigpen's reedy organ lines. Alternate versions of stone-cold classics like "Truckin'" and "Ripple" provide a new perspective on history, and the appearance of shelved songs like "Hollywood Cantata," a rare Bob Weir/Robert Hunter collaboration, offer a tantalizing view of what could have been.