Ok, so they aren’t actually called the Beatles in Batman 222 (June 1970), but there is no doubt that the Robbins, Novick and Giordano story was inspired by the “Paul is Dead” notion so popular at the time.
Dick Grayson is back from a college break in this tale, and so Bruce and Alfred return to Wayne Manor, opening it to take in the band, called the “Oliver Twists,” as they begin a tour, after a few years of not having been seen in public. There are rumours that Saul Cartwright from the band had died, and has been replaced by a double.
So Batman and Robin try to figure out if Saul really is who he claims to be. Bruce and Dick pretend that it’s Alfred’s birthday, in order to record the guy singing to him, and then compare the voice prints with those from the old album.
The resolution of the story is hilariously bizarre. Saul really is Saul, but the other three band members are impostors. They had died in a bus accident, and Saul hired and trained replacements, and to divert attention, a spreading the rumour that he was the one who died.