When DJ mash-ups appeared a few years back, they were all about linking strange bedfellows — Nirvana and Destiny's Child, the Strokes and Christina. The best ones made you hear something new in both songs involved — which Collision Course does only in snatches. Billed as the first commercially released mash-up record, this six-song EP is well-constructed: The mix of brassy rhymes and heavy electro-rock on "Big Pimpin'/Papercut" and "Dirt Off Your Shoulder/Lying From You" — featuring new verses and music from the band and Jay — is way more interesting than most rap metal. But too often Jay's world-class flow leaves Linkin Park in the dust, and the juxtapositions are pure novelties and less fun than they should be. If Jay really needed another batch of out-there beats, he only had to hit up Timbaland again.

“Time to Pretend”

Listening to MGMT’s breakthrough song, one might interpret it as being about the excesses of rock stardom, but it’s actually about the duo’s pet praying mantis. Ben Goldwasser and Andrew VanWyngarden told Rolling Stone they got the idea from the insect's jerky movements. The mantis died, but the two bandmates kept the egg sack and allowed the hundreds of eggs to hatch. “We tried to name them all, but they died after a day,” said Goldwasser, with VanWyngarden chiming in, “But the praying mantis dance inspired us.”