It may seem surprising that the author of the most important single body of works for the organ since J. S. Bach apparently never saw an organ until his eighteenth birthday. His first encounter with the instrument which would play such a decisive role throughout his life came while visiting the Meudon home of Marcel Dupré, 1 to whom Messiaen had been directed by his harmony teacher at the Paris Conservatoire, Jean Gallon, who had already noticed his young pupil's facility for keyboard improvisation. A mere eight days later, according to a letter of Dupré written in 1967, Messiaen was already able to play him Bach's C minor Fantasia 2 from memory. He subsequently enrolled in Dupré's cours préparatoire, officially entering his class alongside Jean Langlais and Gaston Litaize following an examination on December 17, 1927. The organist of St. Sulpice was therefore Messiaen's sole organ teacher, leaving a lasting imprint on his playing style, not least in the application of strict legato through rigorous finger substitution, as can be seen in Messiaen's scores all the way through to the Livre du Saint Sacrement. 3 He obtained his premier prix from the Conservatoire on May 31, 1929, the final concours consisting of Bach's D major Fugue BWV 532 and three improvisations (on a Gregorian theme and a fugue subject, followed by a free improvisation). 4 Messiaen's first documented organ recitals took place four months later in the small village of Tencin near Grenoble.