MUSIC MAN ELLINGTON, 76, SON OF LEGENDARY BAND LEADER DUKE.

Byline: Peter Watrous The New York Times

Mercer Ellington, a bandleader who spent much of his career maintaining the musical legacy of his father, Duke Ellington, died Thursday in Gentofte Hospital in Copenhagen, Denmark. He was 76.

The cause was a heart attack, said his son Paul.

Ellington played more than a few roles during his career. At various times, he worked as a salesman, disk jockey, record company executive, composer, trumpeter and as his father's aide. But he was best known for continuing, in one form or another, the Duke Ellington Orchestra after his father's death at the age of 75 in 1974.

For next two decades, he toured with the band, made recordings and was the musical director and conductor of "Sophisticated Ladies," a music and dance revue of his father's music.

Ellington was a well-schooled musician, studying in New York at Columbia University, the Institute of Musical Art and at the Juilliard School of Music. Beginning in the late 1930s, he occasionally led his own band, working with Billy Strayhorn, Clark Terry, Cat Anderson and Carmen McRae.

During World War II, he joined the Sy Oliver orchestra as a trumpeter, and performed and recorded occasionally with his father, all the while leading his own bands.

He was the composer of several important compositions played and recorded by his father's orchestra, including "Things Ain't What They Used to Be," "Jumpin' Punkins," "John Hardy's Wife," "Blue Serge" and "Moon Mist," some of which hint at Strayhorn's influence.

He started managing groups in the mid-1950s, including the orchestra of Cootie Williams, who had left Duke Ellington's band; a decade later, he took over the managerial role for the Duke Ellington Orchestra.

As a musical aide, Ellington helped his father to complete "Three Black Kings" as the senior Ellington lay dying in a hospital. He conducted his father's only opera "Queenie Pie" in Philadelphia and at the John F. Kennedy Center for the Performing Arts in Washington, D.C.

After his father's death, Ellington took over the orchestra; about the same time, he moved to Denmark, which meant that the orchestra never really survived as a major jazz attraction in the United States. In 1978, with the help of Stanley Dance, he wrote a biography of his father, "Duke Ellington in Person" (Da Capo), and in 1988 one of his recordings, "Digital Duke," won a Grammy Award for big band jazz instrumental performance.

He is survived by his wife, Lena; his sons, Paul and Edward; and his daughters, Mercedes and Gaye.