Virgil Thomson (November 25, 1896 – September 30, 1989) was an American composer and critic. He was instrumental in the development of the "American Sound" in classical music. He has been described as a modernist, a neoromantic, a neoclassicist, and a composer of "an Olympian blend of humanity and detachment" whose "expressive voice was always carefully muted" until his late opera Lord Byron which, in contrast to all his previous work, exhibited an emotional content that rises to "moments of real passion".