Gaston Marie [Gaston] Dethier (19/04/1875 - 26/05/1958), an American organist, pianist, and composer of Belgian birth. Born in Liège, he was the son of organist Emile Dethier, the brother of violinist Edouard Dethier, and the uncle of physiologist Vincent Dethier. He studied at the Royal Conservatory in his native city with Alexandre Guilmant. He was awarded premiers prix in organ, piano, harmony, and fugue from the conservatory. In 1886, at just 11 years of age, Dethier was appointed organist at the Église Saint-Jacques-le-Mineur de Liège. He eventually left there to work in the same capacity at the Église Saint-Christophe de Liège. He emigrated to the United States in 1894 where he eventually became a naturalized citizen. He was organist at The Church of St. Francis Xavier from 1894 until 1907. He taught organ on the faculty of the Juilliard School from 1907 until 1945. Among his notable pupils were Ray Lev, Marcelle Martin, Carl McKinley and Georges-Émile Tanguay.