Marguerite Marie-Charlotte Long was born in Nîmes, France. She studied first in her native city and then at the Paris Conservatoire, taking a premier prix in 1891, and privately with Antoine François Marmontel, whose other students included Bizet, Albeniz, and Debussy. She made her orchestral debut in 1903 with a performance of César Franck’s Variations Symphoniques with the Lamoureux Orchestra. From 1906, she taught at the Paris Conservatoire, and in 1920 became professor of piano. She also gave private tuition. She married Joseph de Marliavel, who was killed in World War I. In 1919, she gave the first public performance of Le tombeau de Couperin by Maurice Ravel, who had dedicated the last section to her husband. From 1921, she also taught at the École Normale de Musique and gave master-classes on the works of Fauré and Debussy. In 1932, she premiered Ravel's Piano Concerto in G major, which was dedicated to her. In 1941, she retired from the Conservatoire and opened her own music studio. Her three books, containing anecdotes as well as instruction, were published posthumously: At the Piano with Fauré, At the Piano with Debussy, and At the Piano with Ravel. She and violinist Jacques Thibaud established the Marguerite Long-Jacques Thibaud International Competition for violinists and pianists, which takes place each year in Paris. Since 2011, the competition has included singers and is now known as the Long-Thibaud-Crespin Competition.