Sidney Seidenman, who was known simply as "Sidney" during the decades that he led his orchestra at Presidential inaugural balls and other social events in Washington, died of heart failure Wednesday at the Wisconsin Avenue Nursing Home.He was 83.

For more than 40 years, "Music by Sidney" was a byword on the Washington social scene. He played at the old Wardman Park Hotel, and for 41 years at the Mayflower. He played at embassy parties, debutante parties and wedding parties and all manner of soirees. He once played for a ball in the Virginia "hunt country" and then was awakened after a few hours of sleep to play for a "breakfast ball."

In 1967, the year after he stopped playing in the dining room of the Mayflower, he told an interviewer about the time he and his dance band provided music at a party at which the guest of honor was a horse named "John the Baptist," and about a "macabre" occasion when a woman asked him to play over the grave of a friend.

"When we got there, she said the only thing she wanted played was her friend's favorite piece of music" he said. "So I stood in the cold, with the wind blowing, and played the 'Volga Boatman.' I caught a terrible cold and never got paid."

Mr. Seidenman was born in Baltimore and grew up there. He began playing the violin when he was 9. By the time he was 15, he was playing regularly in a tearoom, and by the time he was 20 he was leading an orchestra that played music to accompany silen movies.

He came to Washington in 1919, and played first at the Wardman park. Then he moved to the Shoreham, which was located at 15th and 11 Streets NW in those days. In 1925, he began his 41-year engagement at the Mayflower.

In later years he established Sidney's Orchestras, Inc. By the time of his retirement in the late 1960s, he had nine orchestras that were playing up to 800 engagements a year.

Mr. Seidenman was a member of the Washington Hebrew Congregation and the Kiwanis Club of Washington.

Survivors include his wife, Sylvia, of the home in Washington; a daughter, Mr. Emil C. Hess, of Brimingham, Ala.; a son, Sidney Jr., of Washington; four sisters, Mrs. Gerald Rosenour, of Baltimore, Mrs. David Sonneborn, of Sarasota, Fla., Mrs. Coleman Harrison, of Pittsburgh, Pa., and Mrs. Edward Blistein, of Burlington, Vt.