From The New York Times:
Einstein once said that while Beethoven created his music, Mozart’s “was so pure that it seemed to have been ever-present in the universe, waiting to be discovered by the master.” Einstein believed much the same of physics, that beyond observations and theory lay the music of the spheres — which, he wrote, revealed a “pre-established harmony” exhibiting stunning symmetries. The laws of nature, such as those of relativity theory, were waiting to be plucked out of the cosmos by someone with a sympathetic ear.
Thus it was less laborious calculation, but “pure thought” to which Einstein attributed his theories. Einstein was fascinated by Mozart and sensed an affinity between their creative processes, as well as their histories. As a boy Einstein did poorly in school. Music was an outlet for his emotions. At 5, he began violin lessons but soon found the drills so trying that he threw a chair at his teacher, who ran out of the house in tears. At 13, he discovered Mozart’s sonatas.
From 1902 to 1909, Einstein was working six days a week at a Swiss patent office and doing physics research — his “mischief” — in his spare time. But he was also nourished by music, particularly Mozart. It was at the core of his creative life. And just as Mozart’s antics shocked his contemporaries, Einstein pursued a notably Bohemian life in his youth. His studied indifference to dress and mane of dark hair, along with his love of music and philosophy, made him seem more poet than scientist.
More here.