I've never seen 'Caligula', nor am I interested in remedying that. I'm well aware that it was produced by Penthouse Magazine and labored through a number of artistic disputes. In short, many of the cast and crew were not pleased with 'Caligula', and perhaps composer Nicolai used the pseudonym Paul Clemente to distance himself from the project.
Below is the aforementioned track 'Isis Pool' with footage from the movie. FYI, the footage does not contain explicit content, and I suspect it's either from the R-rated version or perhaps even fan-made.
This will be one of the few peplum entries for which I don't own the soundtrack on CD. It's pretty rare. Someday I'll stumble upon this release and add it to my collection.