United States of America, United States of America (1968)
The album (per Wikipedia) is based largely around synth-maestro and political radical Joe Byrd and his then-girlfriend, singer Dorothy Moskowitz. And while much of the music can be slotted in alongside other contemporaneous psychedelia, from the Jefferson Airplane to the Byrds to the West Coast Pop Art Experimental Band, it stands apart through its reliance on synthesizers and electronic sound effects rather than guitars, as well as more deliberately exotic musical influences and stray weirdness that calls to mind everything from avant garde classical music to Frank Zappa.
Take the opening track, "The American Metaphysical Circus," which opens with the sounds of a carnival merry-go-round before sliding into a haunting ballad with Moskowitz's ethereal vocals intoning the refrain, "The cost of one admission is your mind," pretty much setting the scene for the rest of the album.
It's not all trippy weirdness, though; the second track, "Hard Coming Love," is a more traditional, bluesy number that sounds like much of what was coming out of San Francisco in the Summer of Love; while "Coming Down" is a flowery psychedelic pop song. But as a package, it's pretty off-kilter, if not downright jarring at times, but it's also completely distinctive and consistently fascinating.
The CD reissue I have (and the version on Spotify) is doubled in length with various outtakes and follow-up tracks recorded before the band broke up; many of these are as good as much of the album, with a more grounded, less experimental sound and actual guitars in lieu of electronics (i.e. the dated but fun "You Can Never Come Down" and the Airplane-esque "Tailor Man").
Here, why not lose your shit to "The American Metaphysical Circus":