Thomas Stewart, bass-baritone at the Met, Bayreuth Festival

ROCKVILLE, Md. -- Thomas Stewart, the American bass-baritone praised for his portrayals of the god Wotan and other Wagnerian roles at the Metropolitan Opera and the Bayreuth Festival, has died. He was 78.

Mr. Stewart died Sept. 24 after collapsing while playing golf near his home in Rockville. He was taken to a hospital, where he was pronounced dead from a heart attack.

Mr. Stewart was known as a commanding singer who took an imaginative approach to his diverse roles, which included Aeneas in Purcell's ``Dido and Aeneas," Jochanan in Richard Strauss' ``Salome," and the title role in Mozart's ``Don Giovanni."

Matthew Epstein, director of the worldwide vocal divisions at Columbia Artists Management, said Mr. Stewart was ``deeply musical, able to sing in many different styles and languages, a wonderful actor with a fabulous vocal technique."

A Texas native, Mr. Stewart nurtured young singers as part of the Evelyn Lear and Thomas Stewart Emerging Singers Program, in company with the Wagner Society.