The background singers came to the forefront when Motown veterans Gladys Knight and the Pips hit the Warner Theatre last night, their act polished to a high gloss after more than 20 years of hits.

Dazzling in a platinum suit, and looking (and moving) impossibly young, Knight was a joy to watch and listen to, working the crowd with genuine affection. Her husky, powerful contralto connected as urgently as ever on the chestnuts and on newer songs, like her wrenching but controlled version of "I Am Telling You I'm Not Going" from "Dreamgirls."

The Pips (her older brother and two cousins), always a fast and funny visual counterpoint with their sleight-of-body moves, provided a catalogue of intricate steps.

Knight's Vegas-slick set, mostly medleys, was a dizzying tour of memories, but several songs suffered from the speeded-up pace.

Bloodstone opened with an entertaining set of smooth soul harmonies, including its '70s hit "Natural High." Young local comic Greg Cooper ran through the standard roster of impressions between acts, then scored a direct hit with his hysterical, historical encyclopedia of the male soul greats, from James Brown to a devastating parody of Rick James.

Knight and Bloodstone return tonight at 8 and midnight.