Hammond was born in
New York, christened John Henry Hammond Jr., although both his father and paternal grandfather shared the name. He was the youngest child and only son of John Henry Hammond and
Emily Vanderbilt Sloane. His mother was one of three daughters of William Douglas Sloane and
Emily Thorn Vanderbilt, and a granddaughter of
William Henry Vanderbilt. The family lived at the
John Henry Hammond House in
Manhattan. His father attended
Yale University, and graduated with a law degree from
Columbia Law School. His grandfather was Civil War General John Henry Hammond, who married Sophia Vernon Wolfe. His father was a brother of
Ogden H. Hammond, ambassador to
Spain, and uncle to politician
Millicent Fenwick. Despite the family fortune from his mother's side of the family, which included wealth from the
W. & J. Sloane chain, his father worked to provide for his family and maintain the family fortune. He worked "as a banker, lawyer, and railroad executive". Hammond had four sisters: Emily, Adele, Rachel, and Alice. The youngest, Alice, married
Arthur Duckworth in 1927, and then, after divorcing him, the musician
Benny Goodman in 1942. Well-known clergyman and peace activist
William Sloane Coffin Jr. was a cousin. Hammond showed interest in music from an early age. At four he began studying the piano, then switched to the violin at age eight. He was steered toward classical music by his mother but was more interested in the music sung and played by the servants, many of whom were black. He was known to go down to his basement to listen to the upbeat music in the servants' quarters. He loved
Sir Harry Lauder's "
Roamin' in the Gloamin'". While he was in the basement, the rest of his family in the greater part of the five-story mansion would listen to "the great opera tenor
Enrico Caruso, as well as to standard classics by
Beethoven,
Brahms, and
Mozart". In 1925, 14-year-old Hammond graduated from the elementary
St. Bernard's School, then persuaded his family to send him to
Hotchkiss School due to its liberal curriculum. Hammond's love for music flourished. However, he felt limited by boarding school. Hammond convinced the headmaster to allow him to go into New York City every other weekend, a rare privilege, so that he could take lessons from Ronald Murat. However, the headmaster was not aware that outside his formal lessons, Hammond would go up to Harlem to hear jazz. During this time, he said, he heard
Bessie Smith perform at
The Harlem Alhambra, but her biographer disagrees about the dates. In the fall of 1929, Hammond entered
Yale University as a member of the class of 1933. He studied the violin and, later,
viola. He felt a disconnect with his fellow students and felt that he was already well acquainted with the professional world. He made frequent trips into New York City and wrote regularly for trade magazines. In the fall of 1930, Hammond had to withdraw due to a recurring case of
jaundice. Hammond had no desire to a repeat a semester, which contributed to his dissatisfaction with the university lifestyle. Much to the disappointment of his father, a Yale alumnus, in 1931 he dropped out of school for a career in the music industry, first becoming the U.S. correspondent for
Melody Maker. ==Career==