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.

“All Along the Watchtower”

Jimi Hendrix got hold of Bob Dylan's early John Wesley Harding tapes and in late 1967 recorded a version of "All Along the Watchtower" with the Experience in London. Dissatisfied with that first development, Hendrix brought those tapes with him to New York in early 1968 when he began work on Electric Ladyland. Eddie Kramer, Hendrix's engineer at the time, told Rolling Stone that Hendrix "was still looked upon by his basically white audience as the mammoth black guitar hero. There was a constant fight within him to expand himself." Hendrix's successful take on Dylan's work has long been recognized by the songwriter. "I liked Jimi Hendrix's record of this and ever since he died I've been doing it that way," Dylan wrote in the liner notes to his Biograph box set. "Strange how when I sing it, I always feel it's a tribute to him in some kind of way."