One of the main reasons is because the film is so popular (it was recognized as one of the first colour feature films).
This would make the film a modern staple despite its age.
The Great Chain of Being refers to hierarchy in a system,which definitely exists in Dante's Inferno. You can see as the protagonist goes through Hell that first he goes into Limbo, where the least serious criminals and people who haven't been Christened are located. As he goes through nine circles of Hell, he comes across more serious offenders and demons who guard them, until he comes into the very core of Inferno where Satan is keeping 3 people prisoners: Judas, Brutus, and Cassius.
Hope this helps! :)
It's an f clef not a c clef because it's located on the f note i would know considering the fact that i've played piano for 3 years
score based on its axis because it turns real