Long before Kurt Cobain and company formed a band called "Nirvana," there was a British act releasing music under that name. While Cobain and band were the poster-boys of grunge music, the earlier Nirvana was a psychedelia meets proto prog act. This new release is a reissue of their 1971 album with a couple bonus tracks. Perhaps not everything here is progressive rock, but the general concept clearly is, and so is a lot of the music. However you label this, though, it's quite an intriguing release. It should be noted that the main guy in this act (I suppose one could call him, this Nirvana's Cobain) was Patrick Campbell-Lyons, who we've covered previously.
This review is available in book format (hardcover and paperback) in Music Street Journal: 2017 Volume 4 at lulu.com/strangesound.