Daniel Gregory Mason (Brookline, Massachusetts, November 20, 1873 ? Greenwich, Connecticut, December 4, 1953) was an American composer and music critic.
Mason came from a long line of notable American musicians, including his father Henry Mason, and his grandfather Lowell Mason. He studied under John Knowles Paine at Harvard University from 1891 to 1895, continuing his studies with George Chadwick and Percy Goetschius. In 1894 he published his Opus 1, a set of keyboard waltzes, but soon after began writing about music as his primary career. He became a lecturer at Columbia University in 1905, where he would remain until his retirement in 1942, successively being awarded the positions of assistant professor (1910), MacDowell professor (1929) and head of the music department (1929-1940). He was elected a member of Phi Mu Alpha Sinfonia Fraternity, the national fraternity for men in music, in 1914 by the Fraternity's Alpha Chapter at the New England Conservatory in Boston.
After 1907, Mason began devoting significant time to composition, studying with Vincent D'Indy in Paris in 1913, garnering numerous honorary doctorates and winning prizes from the Society for the Publication of American Music and the Juilliard Foundation.
Among the composer's closest friends was E. A. Robinson. The two met in Cambridge in 1899.
Mason's compositional idiom was thoroughly romantic. He deeply admired and respected the Austro-Germanic canon of the nineteenth century, especially Brahms; despite studying under D'Indy, he disliked impressionism and utterly disregarded the modernist musical movements of the 20th century. Mason sought to increase respect for American music, sometimes incorporating indigenous and popular motifs (such as popular songs or Negro spirituals) into his scores or evoking them through suggestive titles, though he was not a thorough-going nationalist. He was a fastidious composer who repeatedly revised his scores (the manuscripts of which are now held at Columbia).