As one of the earliest forms of a cappella singing every group should know at least some of the doo wop classics. "Under The Boardwalk", the 1964 hit by the Drifters, is one of the all time a cappella standards and probably should be in every group's repertoire. Here's a super doo-wop arrangement of Ben E King's 1961 "Stand By Me" and a lovely medley by Ed Lojeski of four doo wop gems. These songs are always crowd pleasers.