Samuel Osborne Barber II (March 9, 1910 – January 23, 1981) was an American composer of orchestral, opera, choral, and piano music. His Adagio for Strings is his most popular composition and widely considered a masterpiece of modern classical music. He was twice awarded the Pulitzer Prize for music, for his opera Vanessa and his Concerto for Piano and Orchestra. His Knoxville: Summer of 1915, a work for soprano and orchestra, was an acclaimed setting of prose by James Agee.