Loeffler was a fastidious composer who composed carefully, frequently revising his compositions. Some of his works are lost. His best-known works include the symphonic poems "La Mort de Tintagiles" (after Maeterlinck), "La Bonne Chanson" (after Verlaine), "A Pagan Poem" (after Virgil), and "Memories of My Childhood (Life in a Russian Village)", as well as the song-cycle "Five Irish Fantasies" (to words by W. B. Yeats and Heffernan), and the chamber works "Music for Four Stringed Instruments" and "Two Rhapsodies" for oboe, viola and piano. The Music for Four Stringed Instruments was written in 1917 after his friend John Jay Chapman's son Victor became the first American aviator to die in World War I. Chapman published his son's letters in 1917and Loeffler was inspired to write this string quartet as a combination meditation and memorial.