French musicologist Henry-Louis de la Grange was born in Paris on 26 May 1924 to an American mother and French father. His teachers included Yvonne Lefebure and Nadia Boulanger, but he also studied at Yale.
He discovered the music of Gustav Mahler in 1945 and spent many years researching the composer, meeting the composer's widow Alma Mahler, collecting material and producing a multi-volume definitive Mahler biography.
He also lectured on Mahler internationally, directed music festivals, broadcast on radio and television, and worked as a music critic.
Henry-Louis de la Grange died in Lonay, Switzerland, on 27 January 2017, aged ninety-two.