This one has been hard to find for years (at least in semi-watchable form), so I'm happy to say I've finally seen it and it's ok. A dubbed Donald Pleasance plays a creepy music peddler or something who gives an all-girl pop band an old piece of sheet music that was apparently composed by a crazed composer who used human heartstrings for strings on his violin. They end up in a secluded country estate owned by Daria Nicolodi to shoot a music video for their newest hit and they end up opening up a portal to hell or something to that extent.

To be honest, this movie was confusing as all hell. I never knew what was going on or what the rules were, but it's a pretty short movie and there are some fun effects and sequences that kept my interest. It's definitely far from the worst horror movie I've ever seen, but it's hard to not see it as a missed opportunity. The ending has a fun twist, too.