The Fab Four will probably always be the most popular rock n’ roll band of all time. And yet, more than 50 years after the rise of John, Paul, George, and Ringo, there are still some lingering questions about the band and tis songs.

Did Yoko Ono really break up the Beatles?

It has to be the biggest myth and most contentious statement in music—that John Lennon’s second wife, conceptual artist Yoko Ono, infiltrated the band, pit the members against each other, and led to its collapse in 1970. By the time Lennon married Ono in 1969 (and soon started to record music with her), the band was already fracturing due to competing egos, differences in opinion on musical direction, and the pressure of being in the most famous group on the planet. In 2013, Paul McCartney himself set the record straight, saying that Ono “certainly didn’t break the group up,” because Lennon was “definitely going to leave” because of “the band’s unhealthy rivalry.”

What’s a “B.O.A.C.,” and how do you fly one?

The largely weird and challenging double-album The Beatles, a.k.a. “The White Album,” what with its stark white cover, opens with a 1950-style old-time rock n’ roll throwback, “Back in the U.S.S.R.” Paul McCartney delivers the song’s first line, “Flew in from Miami Beach, B.O.A.C.” That anagram is lost on listeners not around in 1969, or who weren’t avid air travelers from the U.K. at the time—which the jet set Beatles definitely were. B.O.A.C. is short for British Overseas Airways Corporation, a state-owned airline that specialized in long-haul international flights. In 1974, it merged with two other airlines to become British Airways.

Did they really record backwards messages in their songs?

The Beatles were responsible for a lot of innovations in music, and one of them was “backmasking,” or recording secret messages and then placing them into songs—backwards. Listeners would have to carefully play the album in reverse on a turntable to hear the message. The band stumbled on the idea while recording Rubber Soul in 1965, and used the technique on the song “Rain,” which features John Lennon’s vocal track played in reverse. Then they started placing messages in other songs on their next albums, including apparently in “Revolution #9.” A conspiracy theory quickly spread that claimed Lennon says, “turn me on, dead man,” which somehow meant that Paul McCartney had died and was replaced with a double. There were apparently “clues” in other backwards messages—Lennon’s “I’m very bored” on “Strawberry Fields Forever” sounded a lot like “I buried Paul,” for example.

What’s “Lucy in the Sky With Diamonds” really about?

The Beatles were experimenting a lot in 1967, the year of this song’s release, both with music and substances. The result: This psychedelic-styled song with lots of out-there psychedelic imagery that sounds like it was inspired by an assisted journey through the mind. (For example: “Rocking horse people eat marshmallow pies” and “the girl with kaleidoscope eyes.”) And yet John Lennon insisted throughout his life that “Lucy in the Sky With Diamonds”—of which the first letters of the main words spell out “L-S-D”—that the song was based on a far-out drawing his son Julian made in preschool that he said depicted “Lucy, in the sky. With diamonds.”