In the Hadley home, the two brothers played string quartets with their father on viola and the composer Henry F. Gilbert on second violin.

[1] Hadley loved the artistic atmosphere of the city, where he could attend countless concerts and operas, and where he occasionally saw Brahms in the cafes.

He returned to the United States in 1896 and took a position as the musical instructor at St. Paul's Episcopal School for Boys in Garden City, New York, where he worked until 1902.

He also found prominent conductors to perform them, such as Walter Damrosch, Victor Herbert, John Philip Sousa, and Anton Seidl.

In an age when American orchestras preferred European conductors to home-grown ones, Hadley felt that he needed to establish himself in Europe.

Hadley composed his symphonic poem Salome in 1905, not realizing that Strauss, whom he greatly admired, was working on an opera on the same subject.

The work was eventually performed in at least 19 European cities, and he was invited to conduct it, along with his newly finished third symphony, with the Berlin Philharmonic in 1907.

Hadley encountered some difficulties in San Francisco, where he tried to turn a group of theater musicians into a first rate orchestra.

He brought a number of excellent musicians from the east, including his brother Arthur, to be principals in the new orchestra, but this created some resentments among the locals.

In 1918 he married the lyric soprano Inez Barbour, whom he had met in San Francisco, and who recorded his music as early as 1915.

His visit to Asia was met with great enthusiasm, and he composed a new orchestral suite, Streets of Pekin, inspired by a side trip to China, and led its world premiere with the Japanese orchestra.

Though his operas Azora and Cleopatra's Night received the most attention, his comedy Bianca, which won a prize offered by the American Society of Singers for the best chamber opera in English, perhaps due to its modest demands, received a number of performances during Hadley's lifetime and a few afterwards, even in Japan in the early 1950s.

In the spring of 1934, Hadley scouted the Berkshire Hills of western Massachusetts for a site and support for his seasonal music festival.

Within a few months they staged three days of concerts in August with Hadley conducting sixty-five members of the New York Philharmonic Orchestra.

[1] The majority of Hadley's personal papers and scores are housed in the Music Division of The New York Public Library for the Performing Arts.

During his lifetime, Hadley's music was immensely popular, and was a regular part of the repertory of America's top orchestras, and was also performed in Europe.

Many legendary conductors performed his music, including Gustav Mahler, Leopold Stokowski, Serge Koussevitzky, and Karl Muck.

Other recipients included Sigmund Spaeth, Mayor Fiorello LaGuardia, Samuel Barber, Leopold Stokowski, Martha Graham and Nadia Boulanger.