Is it an album, an EP, a DVD or all three?

Please pick up your pencils and ponder this equation: DVD + EP = No. 1 CD.

It’s not algebra; it’s a novel music-industry formula that will make a splash on the U.S. album chart this week, as well as the chart that tracks music DVD sales.

On Wednesday, when Nielsen SoundScan releases both charts, the same title will probably be No. 1 on both: “The New Breed” by rapper 50 Cent. That title could apply to the product itself: It has two discs, one of them a two-hour DVD and the other a CD with three songs (Consumer note: Some of the newer pressings have four tracks), which would be classified as an EP, not a full-length album. So why is it vying for No. 1 on the album chart?

Among the reasons is that “The New Breed” has more than a dozen songs, if you count both discs, and that its pricing ($14.99 in many stores) and packaging are album-like. And a DVD presence in the music CD aisles of stores has become somewhat the norm. For example, Interscope Records, the label behind the 50 Cent hybrid, has bundled free DVDs with some full-length albums to lure fans who might otherwise pluck new releases for free online.

“The New Breed” is also not the first hybrid to appear on both the CD and DVD charts -- Alanis Morissette, the Beatles and Josh Groban have done it. But it is by far the hottest seller in the bunch.

Groban’s “In Concert” hybrid, for instance, sold 330,000 copies in 2002, enough to make it No. 1 on the year-end tally of music DVDs. 50 Cent’s new release may sell 300,000 its first week.

Retailers are happy to have some life injected into the music DVD scene, which has remained a relatively meek genre for the format. Music industry thinkers, too, are hailing the creation of “event” music DVDs as a way to defuse online music piracy.

Still, purists may long for the day of albums without pull-down menus. That group won’t be happy to hear from Geoff Mayfield, director of Billboard charts: “The idea of what an album is will change even more in the months and years to come.”

-- Geoff Boucher