David Bowie wants you to make some ch-ch-changes to his tunes.

The Thin White Duke is giving fans a chance to bootleg his music by using computer software that allows them to create "mash-ups" of his work, that is, mixing parts of songs from his classic catalogue with tracks from his latest release, Reality.

Bowie, 57, announced a contest on his BowieNet Website seeking entries for review by a panel of judges. Bowie himself intends to select the top track after the contest closes on May 17 and release the tune as an MP3 single. The deejay responsible for the track wins a new car.

Already, a mash-up of "Rebel Rebel" with Bowie's new rocker "Never Grow Old" recently served as the soundtrack to an Audi commercial.

The erstwhile Ziggy Stardust--always one to stay ahead of the technology curve--told London's Times on Monday that "mash-ups were a great appropriation idea just waiting to happen."

"Being a hybrid maker off and on over the years, I'm very comfortable with the idea and have been the subject of quite a few pretty good mash-ups myself," Bowie said.

Mash-ups have been a part of the mainstream musical lexicon for the past two years, proliferating thanks to the advent of song-swapping sites like KaZaA and new software that can strip vocals from one song and lay them over music of another.

Deejays debuted their pirated creations in underground clubs and the tunes quickly began outselling regular discs, causing consternation among major record company execs anxious about protecting the copyrights to their cash cows.

Bowie became clued in to the increasingly high-profile mash-up scene in recent months, as releases like Danger Mouse's The Grey Album, an unauthorized blending of the Beatles' White Album with Jay-Z's Black Album, become Internet smashes. The Grey Album's success was inadvertently bolstered by EMI, the Beatles' label, which tried to halt distribution of the album and wound up only fueling interest.

Bowie told the Times that he and his producer Tony Visconti used to sit around and dream of doing the very same thing back in the '70s--for example, building on the styles of a number of influential groups, say the Doors and the Stones and combining it with Hendrix or even the Supremes to create something new.

While the pair never followed through, the "Fame" singer is more than game to let the imaginations of today's turntable wizards run wild.

He's not the only artist to encourage mash-ups.

Christina Aguilera's camp initially tried to block "Stroke of Genius"--one of the earliest, most popular mash-ups, combining her "Genie in a Bottle" with the Strokes' "Last Night." Now, however, Aguilera has hired the producer of that mash-up, Freelance Hellraiser, to remix her next single.

Meanwhile, British trio the Sugarbabes' scored a number one hit in the UK in 2002 with "Freak Like," which mixed together Gary Numan's song "Are Friends Electric" with Adina Howard's "Freak Like Me." In that case, both the original artists' granted permission for their material to be used.

And, according to the Times, after liking a remix of Elvis Presley tracks, Paul McCartney is even considering getting in on the game, giving his approval to an official album of mashed-up Beatles tunes--that is, if a deal can be struck with Ringo Starr, Yoko Ono and George Harrison's estate. (One of biggest tracks to make the Internet rounds of late is Go Home Productions' "Karma in the Life," which combines the Beatles "A Day in the Life" with Radiohead's "Karma Police.")

For those wanting more from Bowie than morphed tunes, the rock icon is on the road on his 39-date North American Reality Tour. Bowie plays Austin, Texas, on Tuesday and then continues criss-crossing the continent, winding up in Holmdel, New Jersey on June 5, before heading over to Europe.