Aichuk

I just wanted to know about really good music films. First rule: No Documentaries!. Mockumentaries and biopics are welcome though.
The films don't have to be about music, but music has to be an important part of the film (e.g High Fidelity) and/or there should be lots of music references.

Ok I'll start by listing some:

Almost Famous (amazing film, truly an epic and one of my favourite films)
High Fidelity (a quirky romantic comedy which mentions many musicians)
Ray
This is Spinal Tap
School of Rock