Jump to Appearances When the Beach Boys formed in late summer 1961, they were neither accomplished musicians nor a cohesive musical group.  Brian Wilson, 19, had been playing piano and organ at home for many years, mastering the intricate vocal jazz harmonies of his musical idols the Four Freshmen after three years of intense home study of their albums.  His brother Carl, not quite 15, had received an electric acoustic guitar for Christmas 1958 and, along with his friend and neighbor, David Marks, 13, had taken a few lessons from John Maus, later of the Walker Brothers fame.  Carl and David were enamored with the first wave of Rock ‘n’ Roll with Elvis, Little Richard, Fats Domino, and enjoyed learning the guitar stylings of Chuck Berry and Duane Eddy.  Brian’s Hawthorne High School classmate, Al Jardine, 19, had been playing acoustic guitar for many years and in late 1958 formed a trio at school which emulated the folk sensibilities of the Kingston Trio.  The other two members of the band, Dennis, the middle Wilson brother, …