Last night I was reading Inside the Music of Brian Wilson by Philip Lambert (also published by Continuum) and learned this little tidbit: the original working title of Carl's Big Chance was Memphis Beach! Although likely inspired by the chunka-chunka guitar rhythm from the Chuck Berry tune (a recent hit for Johnny Rivers at the time), it's also an eery sign of the future friendship between a kid from California and a kid from Memphis.
I came across an outtake of the Beach Boys doing an impromptu version of The Letter sometime in the late 60s. Knowing of Alex's affection for the Beach Boys, I asked him over the phone if he'd ever heard it. His reply, "I think so."