Excellent addition to any prog rock music collection
For those who grew up in the 1960s, or even those that didn't but lived where there was a decent rock station that played plenty of music from that era (that is, not an oldies station), you probably have heard "I Had Too Much to Dream Last Night". That band was from a Los Angeles-based psychedelic band Electric Prunes. They managed to release three albums in 1967, Mass in F Minor being their third album (they would release two more album in 1968 and 1969 as well). They went and tried something completely different: they recorded a rock Mass. That means there are six songs, with titles like "Kyrie Eleison", "Credo", "Sanctus", etc. All songs stick strictly to the Latin text, and the results is a pretty interesting, combination of Gregorian chanting with the psychedelic rock you come to expect from that era.