Lionel Batiste, the vocalist, bass drummer and assistant leader of New Orleans’ Treme Brass Band, has died. He was 81.Fans of the HBO series “Treme” may not have known Batiste by name, but they often saw him close up. He was the skinny guy with the big drum in the band, one of the acts regularly featured on the show. Batiste died Sunday at a hospital just outside New Orleans. Batiste, known as “Uncle Lionel,” had been ill for about a month, said band leader Benny Jones Sr. He said Batiste had been with the band since it was formed in 1995 but had played bass drum since childhood. Batiste used his drum to stay afloat in the floods after Hurricane Katrina, clarinetist Michael White said. “The water kept rising,” White said. “He couldn’t swim. The water was too high for him to walk out. He saved himself by floating out on top of his bass drum.” Batiste’s singing voice was “somewhere between blues and old-time gospel, kind of raspy but with a nice quality to it,” White said. He recalled that in the late 1960s, Batiste wasn’t playing but “second-lining” — dancing and strutting with a decorated umbrella to the band’s music — and acting as grand marshal for parades and jazz funerals. “He would bring joy and just New Orleans spirit. … He made people feel good about themselves and about living,” White said. The “Treme 2012″ bicentennial poster is a photograph of Batiste and his drum. “I’m broken-hearted,” said actor Wendell Pierce, who played trombonist Antoine Batiste on “Treme.” “He’s part of a long line of great musicians and great family. I was honored to have his name, the name of the character I played, and know that his legacy will live on,” Pierce said.