The nation’s only Police Department steel-drum band debuted on the flatbed of a police truck at yesterday’s West Indian American Day Carnival Parade. They were a popular part of the 36th annual procession along Eastern Parkway from Utica Avenue to Grand Army Plaza.

Fifteen members of the NYPD’s marching band got together about a month ago and bought steel drums and instruments, including a cowbell, to complete the new ensemble. Officer Dan O’Malley, when asked how long he’d been playing the cowbell laughed and said, “About 12 hours, how am I doing?”

If the response from the crowd along the barricades was any indication, Officer O’Malley and the 14 other band members were doing just fine. Women in sequined bikinis, men in Bob Marley T-shirts, and vendors of jerk chicken and roasted corn on the cob hooted as they went by.

Even Mayor Bloomberg tried to get into the spirit of the occasion. He climbed aboard the truck to try his own hand at steel drum playing. He was given polite applause. The Police Commissioner, Raymond Kelly, showed more skill than his boss and managed to play in time with two hands.

The two city officials had stiff competition from Haitian-American entertainer Wyclef Jean, who was one of the grand marshals. He received wild ovations from the Caribbean revelers as he marched at the front of the parade with the mayor.

When Mr. Bloomberg went to the barricades to shake hands, a spectator looked disappointed, smiled weakly, and said “We want Wyclef.”

Mr. Bloomberg laughed and happily obliged. He called over the singer-songwriter and then quietly slipped away.

Mr. Jean told reporters later that he and the mayor had spent most of the parade discussing how the city can best funnel charitable contributions to Haiti.

Mr. Bloomberg had wanted to set up a fund to help Haiti in the wake of flooding earlier this Spring but hasn’t gotten it off the ground. Mr. Jean will meet with deputy mayor Dennis Walcott next week to discuss some of his ideas, including a benefit concert for Haitian relief.

While the weather cooperated for the first time in three years, the celebration was marred just before lunchtime when a woman throwing T-shirts to the crowd fell from a truck in the parade. She was pinned beneath the wheels of a flatbed that was following closely behind. The woman, identified by the Associated Press as Celeste Alvarez, 21, of the Bronx, was listed in serious condition.

Also, around 4 p.m., a 21-year-old black male black was stabbed twice in the lower back on Eastern Parkway, between Albany and Troy Avenues, at Crown Heights. The victim was stabbed by another black male, who fled the scene. The victim was listed in stable condition at Interfaith Hospital.