(b Paris, 14 Feb 1843; d Paris, 21 Dec 1919). French pianist and composer of Alsatian origin. In 1853 he entered the Paris Conservatoire where he enjoyed a particularly successful career, winning premiers prix in solfège (1855), piano (by unanimous decision, 1856), harmony and accompaniment (1859) and counterpoint and fugue (1861), as well as a second prix in organ (1861); his teachers included A.F. Marmontel (piano), Ambroise Thomas (composition) and François Benoist (organ). Financial difficulties prevented him from pursuing the Prix de Rome. From 1861 he gave piano lessons, and from 1863 performed regularly, both in Paris and in the provinces. He attended Rossini’s soirées, played in the chamber concerts organized by Alard, and toured with Sarasate. Always popular with the public, he steadily gained a reputation as a virtuoso. In 1887 he succeeded Marmontel at the Conservatoire, where he exercised great influence on the next generation of French pianists; his pupils included Cortot, Risler and Robert Casadesus. The success of a series of harpsichord recitals which Diémer gave at the 1889 Exposition Universelle led to the founding (with van Waefelghem, Grillet and Delsart) of the Société des Instruments Anciens, and prompted him to dedicate considerable time to promoting early music. In 1902 he established a trust fund for a triennial competition, with a prize of 4000 francs, open to male pianists who had won a premier prix for piano in the preceding ten years. Diémer continued to teach and perform publicly until his death. He was named a Chevalier de la Légion d’Honneur in 1889.
Diémer’s virtuoso playing had a reputation for extreme precision and purity, qualities that may be heard in his recording (c1904) of his Grande valse de concert op.37. A more complete sense of his musicianship may be perceived in his long-lined and tonally refined recording (c1904) of Chopin’s Nocturne op.27 no.2. His compositions, primarily for the piano, were described by Fétis as graceful but not lacking in solidity; some of his songs enjoyed considerable success. He also edited piano music, transcribed symphonic movements and opera excerpts for the piano, and published a piano method.