One thing that Roger Troutman excels in is shtick. Example: the former Zapp vocalist has devoted a large portion of his career to the use of a vocoder, an electronic gizmo that makes him sound like a singing computer. When he finally paraded through the crowd to the stage Saturday night at the Warner Theatre, Troutman was dressed in a nautical white tux and was playing a matching rifle-shaped guitar.

A flashy review of Troutman/Zapp songs followed, including "I Can Make You Dance" and "Moving on the Dance Floor." He changed outfits nearly as often as he changed moods, offering Zapped versions of "I Heard It Through the Grapevine," "Word Up," jazz and blues numbers and even Elvis' "Don't Be Cruel." The vocoder voice can become tiresome, though, and when he temporarily abandoned it for a plain ol' harmonica it was a welcome change.

Opening was vocal quartet Force MDs, performing a set of seamless and sugary ballads it describes as the Force MD "quiet storm." In numbers like "Here I Go Again," pretty T.C.D.'s falsetto hit the high notes and it was swoon time in the audience. The group poured on the schmaltz pretty heavily, but just before it became unbearable the quartet broke into a hilarious rap sendup that paid tribute to James Brown, Popeye and TV's Crazy Eddie.

Also performing a set was disco singer Joyce Sims, whose show was done "on track," music biz jargon for performing to prerecorded music. Unlike the rap acts that do this, Sims had enough sense to look vaguely guilty as she went through the motions of her catchy hits, which included "Lifetime Love."