Hi Jothar. The film was a fictional, hilarious spoof of the Heavy Metal/Glam rock industry. But, if I am not mistaken, they did have Spinal Tap albums/CD’s sold in music stores.
The scene with the volume dial on the amp going up to 11 was hilarious, and it was true. Where most amps have a volume that goes up to 10, that one went up to 11, giving it that little extra kick. But there was also the guitar which was so valuable in the collection, that one cannot even look at it or it would lose value. Ok, enough. lol