I'm with Rebecca - I really dig mash-ups. One of my favorite albums of all time is "The Grey Album" by Danger Mouse - the cross-cultural/generational/musical mash-up of The Beatles' "White Album" and Jay-Z's "The Black Album." Though calling it a "mash-up" seems somewhat unfair - the way Danger Mouse sews snatches of John Lennon instrumental seamlessly with Jay-Z flowing is pure sonic bliss. However, "The Grey Album" is sort of a rarity - most musical mash-ups, I find, get old after the first couple of listens, sounding more synthetic. There is something ageless about original music; there is something ephemeral about most mash-ups.
Actually, I think it's telling that Danger Mouse has gone on to do such great work with Gorillaz and Gnarls Barkely, creating original music. The whole mash-up subculture strikes me as a sort of breeding ground for future artists: you work on a trailer mash-up to finesse your editing technique, you work on a music mash-up to try to get noticed for making beats, not specifically as ends in themselves. Really, most mash-ups are just artfully designed jokes - kind of like William Shakespeare writing a dirty limerick for his actor buddies. Can a mash-up ever make you cry?
That being said, I really dig the much-discussed "Boulevard of Broken Songs" - in part because Boulevard of Broken Dreams and Wonderwall are two of my favorite songs (... sorry Lauren), but also because they fit together so well. Unlike most post-Grey Album mash-ups, which seem based on the basic question of "What two completely dissimilar music genres can I slam together," "Broken Songs" brings together two songs into one glorious whole - it's hard to listen to either original song the same way.
Conversely, movie mash-ups - even funny ones like "Brokeback to the Future" - usually just serve to reinforce how much I liked the original movie before modern technology gave editing power to adolescent numbskulls. One guy edited together an entire Robocop/Terminator fight sequence. On one hand, I admire the skillful nature of the editing; but the Film Studies major in me is screaming, "You idiot! You've turned a pair of great action movies - one about a cyborg Christ figure, and one about Reagan-era bureaucracy, both full of sardonic humor and just a bit of genuine humanity - and made them into a pair of action figures for you to play with!"
It's something similar to what I've been feeling this week messing around with a few different mash-up trailers. At first, I was ecstatic about this assignment - running through my DVD collection, finding horrible Trailer Voices and uproarious possibilities ("Harry Potter and the Clockwork Orange," etc). But after awhile, it all felt a bit empty - even when I matched up the dialogue to the mouth movement, I still knew the original line. Maybe music is more malleable, or maybe I'm just too much of a film elitist.
As a corollary, I recommend watching the trailer for last summer's Miami Vice. This is the genuine studio trailer, for a remake of a TV show, which prominently features a studio-sponsored mash-up by Jay-Z and Linkin Park. This means that absolutely nothing you see or hear is really "original," per se, but for some reason, I really dig the trailer - just the right amount of action-movie decadence, fast cars, sex, guns, speedboats, drug deals, you name it. Even though I've since seen and been disappointed by the movie, the preview still works for me. I'm not quite sure why. The movie was made by Michael Mann, one of the greatest working American directors (he also made "The Insider" and "Collateral"), and it's interesting to see a genuine artist basically working on a full-scale, $150 million mash-up - combining the "Miami Vice" brand with a rugged aesthetic completely at odds with the original's pastels - and all the more interesting because the movie is such a bloated mess.