Reclusive WHITNEY HOUSTON stunned fans at the BET 25th anniversary celebration concert on Wednesday night (26OCT05) when she appeared unannounced onstage for a brief a cappella tribute to late pal Luther Vandross.

It was the newly-blonde Houston's first public appearance since she left rehab this summer (05) and guests at the event, held at the Shrine Auditorium in Los Angeles, welcomed her with a minute-long standing ovation.

Meanwhile, Houston's husband Bobby Brown also received a standing ovation when he joined his former boy band New Edition on stage for a medley at the event.

Brown and Houston joined stars including SEAN 'DIDDY' COMBS, Alicia Keys and Mc Hammer in paying tribute to the founders of US cable TV channel BET at the anniversary party.

EARTH, WIND + FIRE, Nelly, Snoop Dogg, LL Cool J, NEW EDITION and Mary J Blige were among the acts who performed at the event, held at the former home of the Oscars.