I'll be quite honest. I didn't understand it, and I doubt I will ever able to from a single viewing. But perhaps in the future when I rewatch it, it might make more sense; all that I took away mostly was that clearly I was missing something in my life before I listened to this type of music. I'm quite shocked and surprised I enjoyed it as much as I did, it reminded me very much of Across the Universe, which personally I didn't really care much for but somehow this movie clicked with me. But I have sneaking suspicions that it has something to do with Oscar Wilde being a space alien. That enough is to make any movie epic.
Apparently it's supposed to be slightly based of David Bowie or something but I really can't tell you since I'm not all that familiar in this genre of music. All I gathered is that Brian Slade, Jonathan Rhys Meyers, is this glam rock icon of sorts but he kinda has feelings for this other rock dude Curt Wild who so happens to be played by Ewan McGregor. He's kinda insane apparently since at the age of 13 he underwent electro shock therapy after "servicing" his brother in the loo. Obviously it didn't help much since he's insane. Christian Bale plays the awkward looking fanboy turned journalist named Arthur or something.
The story is told mainly in a flashback type of mode as Arthur, now a normal looking dude, is a journalist researching about Brian Slade and his subsequent disappearance after a "faked" murder stunt. It's funny I thought that he appeared much younger looking in the "present" scenes than in the "flashback" ones. He just looked like a kind of sad pathetic thing looking for his place in society. Maybe he too was a space alien. That'd make sense.
Throughout it all we gain insight on who this Brian Slade character really was through other people and from Arthur's own memories of the time back then (He was a pretty big fanboy). Lots of fops and dandies make appearances and glitter and feathers randomly fall from the sky. Oh and there's a fairy. Like seriously, this guy's last name is Fairy. He too might be part of the alien conspiracy.
It's just a really really long music video type thing. Some I suppose are covers of other songs and others are original to the movie performed by some musicians of noted merit and the main leads in the film. Lots of drugs, sex, and that sort of stuff. Maybe a bacchanal or two. The important thing I understood from a single viewing was that Oscar Wilde was a space alien, and suddenly everything makes sense.