Movies grab your attention and hold it.... even if it sucks. It's the combination of music, words, story, and visual candy that engages people... ALL people. Movies are the new storyteller. If there was no television, people would likely tell stories to each other rather than listen to music... even live.
Incorporate music into a story and you have a theatrical performance... which could be recorded... and bam! you have a movie.

Anyway, yes, I think people would likely sit around and watch a concert... especially if it's a commonly experienced one. You know, like that Kiss concert where they passed around the cup and we all spat in it.. and they drank it! Holy crap, man... that was awesome!
This experience might be considered similar to looking at a photo album. I think watching movies is a lot like getting to see a photo album in general. It's all story telling with lots of visual information. MOST people are visually stimulated... especially men. So, I find it odd that women aren't more into listening to music... but my guess is that they're not especially auditorily stimulated.
-C