Henry Cowell (/ˈkaʊəl/; March 11, 1897 – December 10, 1965) was an American composer, music theorist, pianist, teacher, publisher, and impresario. His contribution to the world of music was summed up by Virgil Thomson, writing in the early 1950s:
Henry Cowell's music covers a wider range in both expression and technique than that of any other living composer. His experiments begun three decades ago in rhythm, in harmony, and in instrumental sonorities were considered then by many to be wild. Today they are the Bible of the young and still, to the conservatives, "advanced."... No other composer of our time has produced a body of works so radical and so normal, so penetrating and so comprehensive. Add to this massive production his long and influential career as a pedagogue, and Henry Cowell's achievement becomes impressive indeed. There is no other quite like it. To be both fecund and right is given to few.