Before The Byrds were The Byrds, they were five young musicians cutting their teeth in L.A.’s folk clubs and looking for their sound. This fascinating compilation captures the band’s efforts to find its place between Greenwich Village folk and Merseybeat pop. The hallmarks of folk rock are easy to hear, but it’s equally thrilling to discover what got left out, like the military-style drums on a tentative “Mr. Tambourine Man” or the Beatles-esque “Oh yeah”s on “Please Let Me Love You.”