In 1991, Negativland, a long-running “culture-jamming” experimental band, released “The Letter U And The Numeral 2,” a dinky synth version of U2’s “I Still Haven’t Found What I’m Looking For.” It featured a sample of Casey Kasem, the famous radio host, going on an off-script rant during an infamous unbroadcast studio rant. The resulting court battle was long and epic, and it eventually gave Negativland enough material to publish the book Fair Use: The Story of the Letter U and the Numeral 2 in 1995. Kasem died on Sunday, and the members of Negativland have paid him their own sort of prankster tribute by offering “The Letter U And The Numeral 2″ up for remix. You can download the master tracks and do what you will with them here.