By Jon Caramanica
Updated January 17, 2003 at 05:00 AM EST

French house duo Cassius stack their compositions with sounds you don’t typically hear on the dance floor — gospel harmonies, a ringing phone, an exuberant Ghostface Killah rap. Au Reve, their excellent follow-up to 1999’s ”1999,” shows them to be among the least parochial and most proficient of their discofied Gallic peers. House may be home for Cassius; thankfully, though, they never stay in for very long.