Nelson Hatt, 51, a latter-day big band trumpeter who played for films, television, recordings and commercials. A native of San Antonio, Hatt graduated from Rice University, where he studied bio-acoustic music. But he quickly switched to trumpet and in 1969 established himself as a professional musician and private teacher in the Houston area. Hatt specialized in music from the heyday of big bands, playing the works of Woody Herman, Harry James, Buddy Rich and Glenn Miller. After settling in Los Angeles in the 1970s, Hatt became a session musician and produced, among other work, a memorable television commercial about cars featuring Miller's 1940s hit "In the Mood." On Dec. 8 in Glendale of a stroke after heart surgery.