The chemistry between Madonna and Justin Timberlake was obvious when he inducted her into the Rock and Roll Hall of Fame this month. It's obvious, too, on "4 Minutes," the first single from her "Hard Candy" album, due April 29. Not surprisingly, it's a dance-happy track, with hip-hop beats juxtaposed with dark '80s-sounding synths. When J.T. and Madonna trade vocals on the catchy chorus ("we've only got four minutes to save the world"), his part suggests vintage Michael Jackson. The ubiquitous Timbaland, J.T.'s pal, is along for a rap. "4 Minutes" is hardly classic Madonna, but it's bound to be a big winner on the radio and in dance clubs. (Can you say "remix"?)

JON BREAM