French pianist, who was born in Paris and studied at the Conservatory in that city, under Durand, Bazin and Ambroise Thomas. He has also composed much good music and has done a great deal to revive interest in ancient music, especially the works of the harpsichord masters of olden times, and the ancient musical instruments. Diemer became proficient from his earliest years as a pianist. At thirteen he took the first piano prize at the Conservatory, three years later, first prize for fugue, and later, first prize for harmony, second prize for organ and first for counterpoint. In 1887 he was appointed first piano professor at the Conservatory, succeeding Marmpntel. Beside participating in brilliant concerts of modern music, he has organized concerts of ancient music, and played on oldtime instruments. He has appeared with success at the Alard, Pasdeloup and Conservatory concerts, and Widor, Lalo and Saint-Saens have all written pieces for him, which he has given at the Lamoreaux and Colonne concerts in Paris. He came into prominent notice at the time of the Paris Exposition with the rendering of the compositions of harpsichord masters of olden days and the result of his revival of their music was the establishment of the Society of Ancient Instruments. Under his direction this society gave many concerts in London. His works include a concertsttick; songs; characteristic pieces for piano and wind-instruments; and a collection of Clavecinistes frangais, beside chamber-music. He has also edited collections of songs and other music.