Marguerite Long was a pianist and professor at the Conservatoire (1906-1940). She opened her own piano school in 1920. She was married to the musicologist Joseph de Marliave, who died in action in 1914, and to whom Ravel dedicated a movement of Le tombeau de Couperin. It was Marguerite Long who gave a highly emotional first performance of Le tombeau de Couperin in 1919.
She developed a close professional friendship with Ravel in the following years, and gave the first performance of the Concerto en sol, which is dedicated to her, in January 1932. Together they then undertook a triumphant three-month tour of the new concerto throughout Europe.
Marguerite Long was seen by some as a jealous and pushy woman who tried to 'adopt' composers for her own benefit. Previously she had established a close musical relationship with Fauré, presenting herself as the leading interpreter of his piano music, until a rift arose between them over her demands for a teaching post at the Conservatoire. Fauré later described her as "a shameless woman who uses my name to get on". Roland-Manuel claimed that she had forced Ravel to give her the dedication of the Concerto en sol. (See J. Duchen, Gabriel Fauré. London, Phaidon, 2000; p.161-165).
She wrote a volume of memoirs of the composer, Au piano avec Ravel, which appeared in 1971 after her death. (English translation: Long ). It contains detailed advice on the interpretation and performance of Ravel's piano works, and her sketch of the composer's life and character is particularly perceptive.