Mike Brewer and Tom Shipley made a career of writing clever, harmony-laden tunes that doubled as anti-war and anti-establishment screeds. President Richard Nixon hated their biggest hit, 1970's campfire-ready “One Toke over the Line,” while the group hated Nixon on the country picker “Oh Mommy” (which features a killer Jerry Garcia slide guitar part). This set draws the hits and near-misses from their 1968-1973 heyday. From the San Francisco psych of “Fifty States of Freedom” to the comely, Simon & Garfunkel–ish “Ruby in the Morning” to the beautifully tempered version of Bob Dylan’s “All Along the Watchtower,” there isn’t a song here that doesn’t resonate like a beautiful, tuneful epistle to an era.