Klaatu: Klaatu (a.k.a. 3:47 EST) (1976)
But about half of it is also pretty great and absolutely worth checking out.
Klaatu, a Canadian duo (later trio), merged some experimental proggy compositions with surprisingly catchy power pop, kind of an unholy cross between early 10cc and Gong and the Beatles. Indeed, their Beatlesque harmonizing on a couple tracks actually led to some rumors at the time that John and Paul were secretly behind the mysterious band (which did not name its members anywhere on their albums). It seems a little far-fetched, but given the strangeness/inconsistency of some of Paul's 1970s work, it's not entirely indefensible.
The opening track is best known for being inexplicably covered by the Carpenters. It's a crazy, utterly bizarre sci-fi track, starting with some unearthly radio chatter before slipping into a stunningly catchy message to our alien brethren. It's great and astoundingly odd, and hard to imagine why the Carpenters of all people decided to cover it (leaving it pretty much intact other than sweetening it up a bit). The other highlight is "Sub-Rosa Subway," one of the greatest 70s pop songs nobody's ever heard, and presumably the basis for those bizarre secret-Beatles rumors. There's definitely a McCartneyesque vibe to the song (a somewhat detailed narrative of the early construction of the NYC subway, I think), but it's also just relentlessly infectious in its own right. Is it prog? Is it power pop? Dunno. But it's fabulous, in a way that only 70s proggy pop could be.
Beyond those two obvious standouts, there's the relatively straightforward sun-drenched Brian Wilson-influenced West Coast summer pop of "California Jam," the freaky boogie-rock of "Anus of Uranus," the glam rock of "True Life," and the goofy, disjointedly proggy "Doctor Marvello." (The final two tracks on the album are far more problematic; one sounds like a Muppets outtake, and the other is some drawn-out spacey, orchestrated weirdness.)
Their follow-up album, Hope, was comparable -- partly pretty good, partly too damn weird, but the song "We're Off You Know" is another crazy-great McCartneyesque pop song.
Here's a weird lyric video for "Sub-Rosa Subway":