On this day in 1938, Barber’s Adagio for Strings premiered, one of the most celebrated works of 20th-century classical music. Originally composed in 1936 as the second movement of his String Quartet, it was later arranged for string orchestra in 1938. In this clip, you can see it brought to life by Leopold Stokowski and the American Symphony Orchestra rehearsing ahead of the opening concert of Madison Square Garden’s new building. At 85, he conducted with remarkable energy and precision. This ra