Klaatu was a Canadian prog rock band in the 1970s. Being a prog rock band in the 1970s, they were a little out there. You kind of had to be, I think.
For its first record, the group, which was named for a character in the sci-fi cult classic The Day the Earth Stood Still, decided that they would put nothing on the album that identified them as anything other than Klaatu. There were no pictures of the band and no listing of its members, there was no bio or personalized liner notes, and the authorship and performance of all songs was attributed only to "Klaatu." In addition, the group did no promotional appearances and did not tour in support of the album. Through the magic of YouTube, you can listen the whole record here. It's pretty good for what it is (which, remember, is 1970s Canadian prog rock, so dial down your expectations accordingly).
Klaatu's debut did okay, but not great, in the U.S. Released by Capitol Records in September, 1976, it had mostly run its course by the end of that year. But in February, 1977, the album got some surprising new life. Steve Smith, a rock journalist for the Providence (R.I.) Journal, listened to the album and noted some Beatlesque sounds (especially on the song "Sub-Rosa Subway.") Intrigued by the mystery of the album credits, he did some tortured detective work and came up with a theory: Klaatu was actually The Beatles themselves in disguise.
Smith wrote a column titled "Could Klaatu be Beatles? Mystery is a Magical Mystery Tour" in which he laid out his reasoning: (a) a couple songs sounded kind of Beatle-y, (b) Capitol Records was the Beatles' US label for most of their career, (c) Capitol feigned ignorance about the band's identity, (d) Ringo Starr's 1974 album Goodnight Vienna features him dressed as Klaatu from The Day the Earth Stood Still, and (e) (go with me on this one) one of the band's songs called "Bodsworth Ruggleby" was misspelled as "Bodsworth Rubbleby" on the record cover, and "bods," "worth" and "by" "rubble" can be put together to suggest that the band got their value from rocks, and the Beatles started off being known as The Quarrymen. Smith's column ended by leaving four possibilities: either the group was The Beatles, or it was a couple of Beatles, or they were backed by The Beatles, or they were simply "a completely unknown but ingenious and talented band."
From there, the rumors took off. The story was written up in newspapers around the country, and made both Rolling Stone and Billboard magazines. Remember that after The Beatles breakup there was intense interest in a reunion - as noted in TMFW 44, pay-per-view pioneer Bill Sargent offered the Beatles $50 million to play one show. And remember that conspiracy-minded fan theories about The Beatles were already a well-established pastime for rock journalists and DJs and teenagers - Paul died and was replaced by a look-a-like in 1967 and the group left clues everywhere. Klaatu's record found renewed interest, and Capitol Records encouraged the speculation by writing vaguely-worded press releases and referring to the group only in the collective. Most of the clues were pretty tenuous (or outright stupid), but for those who wanted to believe it didn't really matter. Maybe this was the realization of the dream.
Dee Long, one of the three real life members of the band, has an excellent and comprehensive website where he has collected scans of the press coverage that the group got back in those days. One of my favorites is a story in the British music magazine NME, written shortly after the rumors started, titled "Deaf idiot journalist starts Beatle rumour." The copy is similarly toned, calling the rumor "the latest idiotic burble to flourish in the Land of the Credulous" and dismissing the Providence Journal article as "hypothetical drivel" and a "bug-eyed account."
Ultimately, the rumor was short-lived. A radio station in Washington, D.C. thought to visit the Copyright Office to check on the registration for Klaatu songs. Those listed the band's real members, and game was up. Klaatu made four more records in the late '70s and early '80s, but they are now known overwhelmingly not for their music but for their loose, brief connection to the Fab Four.
BONUS FACT: The "Paul is dead" theory has adherents still to this day. Just look at the facial structure, man. It's undeniable.
BONUS FACT 2: The lead song on Klaatu's first record is called "Calling Occupants of Interplanetary Craft (The Recognized Anthem of World Contact Day)." The song was inspired by a real event. According to the band's website, "In March 1953 an organization known as the 'International Flying Saucer Bureau' sent a bulletin to all its members urging them to participate in an experiment termed 'World Contact Day' whereby, at a predetermined date and time, they would attempt to collectively send out a telepathic message to visitors from outer space. The message began with the words...'Calling occupants of interplanetary craft!'"
The story checks out, and in fact World Contact Day is still a thing. From that first link, the idea is that "if both telepathy and alien life [are] real, a large number of people focusing on an identical piece of text may be able to transmit the message through space." Mark your calendar for next March 15 so that you can get in on the alien transmission.
BONUS FACT 3: When the Klaatu rumor first started, the guitarist for The Carpenters checked out their record. He brought "Calling Occupants of Interplanetary Craft" to the group, and within just a few months The Carpenters recorded and released a cover, along with a bizarre-but-wonderful video. Amazingly, the song made the top-40 in the US, hit the top 10 in Canada and the UK, and reached #1 in Ireland. The '70s were a weird time for music.