Basement Jaxx has a habit of making kinds of music that don't exist until Basement Jaxx sits down to make them. The British duo's maniacally inventive jumbles are usually labeled "dance music," but they're more like mutant forms of pop from a planet where gravity pulls beats down hard and gaseous swirls make everything else go weird and woozy. Take "Lucky Star," the first single from Kish Kash: A heavy two-step beat drops in at the start, destroying the floor beneath it, while what sounds like an entire Middle Eastern marching band blows horns and wiggles tambourines with abandon, like cartoon characters scrambling in the air before going into freefall. Instead of plunging, though, they're thrust upward as more sounds pile on, increasingly amplified and frantic. All this happens beneath vocals by Dizzee Rascal, a rapper whose rubbery, circular style inspires its own awed head-scratching (his Boy In Da Corner, still without a U.S. release date, won England's Mercury Prize earlier this year). So go the sketchy specs of just one song on Kish Kash, an album that sets the bar for density and imagination almost unreasonably high. More consistent than 2001's Rooty, the new record shows Basement Jaxx maintaining its cool love for Prince, whose slinky funk prowls in the background. But Kish Kash also shows the production-minded duo stretching into roles as true songsmiths. "Good Luck" is a gleefully menacing kiss-off to an ex-lover: "Good luck in your new bed / Enjoy your nightmares, hon, when you're resting your head," sneers The BellRays' soulful singer Lisa Kekaula. Guests handle most vocal duties, with 'N Sync's J.C. Chasez on the riotous near-rock anthem "Plug It In," goth goddess Siouxsie Sioux on the electroclash coldcock "Cish Cash," and Me'shell NdegéOcello on two simmering soul-stirrers. But Basement Jaxx's Felix Buxton shows off a movingly pensive voice in a song that helps give the disc its emotional tenor, as well as a preening one in a track that sounds like The Rapture gone mariachi. Basement Jaxx's production soars behind fidgets and shrieks, but an overflow of song splashes helps make Kish Kash a masterpiece of a style-slosh commanded by Basement Jaxx and nobody else.