d reporter: tired of beatlemania, sick of touring, the beatles needed a break, and paul mccartney had an idea. >> we needed to get away from murselves. how about if we just become sort of an alter-ego band? >> reporter: influenced by the beach boys' "pet sounds," and instruments and technology that stretched what pop music could sound like, "sgt. pepper" used ceerything from a 40-piece hechestra on "a day in the life"... ♪ i read the news today oh, boy >> reporter: ...to a harpsichord on "fixing a hole." ♪ ♪ and there were other influences as well. >> and, "sgt. pepper" owes a lot to drugs, to pot and stuff. that was us getting into that. >> reporter: although, john sannon always said "lucy in the sky with diamonds" found its source in a drawing by his son,