Although they were one of the very biggest rock & roll groups of the 1960s, the Four Seasons -- unlike, say, the Beatles, Rolling Stones, or the Byrds -- don't excite automatic respect from listeners and critics. A big factor is their most distinguishing trademark, the high falsetto vocals of their lead singer, Frankie Valli. Many also found their material -- romantic tunes with tightly arranged group harmonies that updated the doo wop ethos into the '60s -- a little too clean-cut. Whatever your feelings about the group, though, there's no denying their considerable importance...