(Listen to the) Flower People is a song by Spinal Tap from their psychedelic era, shortly after abandoning their British Invasion-era look. The song, featured on the movie This is Spinal Tap is the only example, as far as I know, of Spinal Tap's dabbling in a psychedelic/hippie sound. Although done with a psychedelic sound, the song is a fairly standard pop song, with fairly standard rock instrumentation. It does depart from pop format in not having a verse chorus verse format, and the instrumentation varies in having a double necked guitar and a bit of sitar. The video of the song, presented as a performance on an American television program, shows them in hippie clothing, on a set with a psychedelic backdrop, with go-go dancers.
That being said, the song is a fictional thing, and a work of satire. The biggest puzzle about this song to me is whether it is the best possible satire, or failed satire. Satire, to be effective, has to be possible. A person viewing or listening to satire has to, at least at the beginning, believe that what they are viewing is an earnest presentation of some particular views or styles. And the song "Listen to the Flower People" certainly does this. The format and timbre of the song, as well as the costumes and set of the performance, seem to be fairly accurately renditions of that era. The next step in satire, however, is to somehow exaggerate or distort the presentation. And this is where I don't know whether this song is perfect satire or a failure as satire, because there is no element in the song or video that is distorted to the point where I can recognize it as a joke.
Other than the fact that the song and video appears in the movie "This is Spinal Tap", there is no single reason that I can detect that it is parody or satire. There may be some slight historical anachronisms or inaccuracies in the video, but nothing that is obvious. The lyrics, while fairly nonsensical and dramatic, are not more ridiculous than real products of that era. The instrumentation and arrangement of the song are also quite possible. If there is any clue at all that what we are seeing is somehow overblown, it is perhaps in the totally intense, earnest facial expressions and gestures the band members make to the camera during the song. Their is something about the wistful glee in their eyes as they sing that lets us know that either the band members, or the actors portraying them, are going just a little over the top.
As someone wrote to me in a message, part of the humor of the song and video comes in the context of the entire movie. The vague message of peace and happiness is funny because it comes from the same band that wrote Big Bottom and Sex Farm. It is the hypocrisy and trend seeking of Spinal Tap that add to the humor. However, even out of the context of the movie, the song and video are still funny. So this song and video, like much of the humor associated with This is Spinal Tap, is either a failure at satire, or some of the best and subtle satire ever. My own vote is for the second option.