Question: Knoxville: Summer of 1915 is a work for voice and orchestra by what American composer of orchestral, opera, choral, and piano music, who is one of the most celebrated composers of the 20th century?
Sentence (from "Knoxville: Summer of 1915"): The work was commissioned by soprano Eleanor Steber, who premiered it in 1948 with the Boston Symphony Orchestra under Serge Koussevitzky.
Relevant evidence: No