Louis Henry Nicolas Thiry (15 February 1935 – 27 June 2019) was a French concert organist, composer and pedagogue. He was professor of organ at the Regional Conservatoire in Rouen and played in concerts internationally. His many recordings include the complete organ works of Olivier Messiaen in 1972, which received several awards and led the composer to describe him as "an extraordinary organist". Thiry was blind. 　　Born in Fléville-devant-Nancy, Thiry, who was blind,[4] studied music first at the Nancy Conservatoire [fr], where he received a first prize in organ (organ class of Jeanne Demessieux) in 1952, followed by studies with André Marchal at Institut National des Jeunes Aveugles in Paris.From 1956, he studied at the Paris Conservatoire with Rolande Falcinelli, graduating in 1958 with a first prize in organ playing and improvisation. 　　He was titular organist of the 1732 Lefebvre organ at the chapel of the Charles Nicole Hospital, part of the University Hospital in Rouen. He was professor of organ in Metz where one of his students was Bernard-Marie Koltès, and held the same position at the Rouen Conservatoire where his students included Alain Mabit, Céline Frisch and Benjamin Alard. 　　He took part in many international festivals, including Lille, the Besançon Festival, the Festival of Paris, Haarlem, Venice and the 1982 Messiaen Festival in Moscow. 　　Thiry died on 27 June 2019 in Mont-Saint-Aignan.