There are two ways of looking at Rhino's Girl Group Greats. First, you could argue that it's unnecessary, since every one of its 20 cuts is known (and probably owned) by girl group collectors. Second, you could argue that it's absolutely necessary, since every one of its 20 tracks forms the essential foundation for a girl group collection. And that's probably the best way to view the collection, since it summarizes all the girl group hits from the early '60s, including cuts from Motown and solo cuts that fit the musical definition, even if they aren't by groups. So, this turns out to be a nearly impeccable collection of early-'60s pop, as not one of these 20 songs could qualify as anything less than indispensible (with the possible exception of Joanie Sommers' "Johnny Get Angry," which still stands as a great artifact of its times). Ultimately, this isn't an album for collectors, but rather something for a listener wanting an immediate immersion into the best of girl groups, and this functions flawlessly.