Rodolphe Mathieu was at first reluctant to teach his son music, and forbade him to touch the piano. This is because the senior Mathieu regarded music as a pauper's profession. Even so, Rodolphe Mathieu resigned himself to teaching his son music, because he recognized the exceptional talent in Mathieu. Mathieu began composing at the age of 4. At age 6 Mathieu gave his first recital of his own composition at the Ritz Carlton Hotel in Montreal, Quebec, on 25 February 1935. In 1936 Mathieu performed his Concertino No.1 for Piano and Orchestra as a soloist on the CBC network. He was later given a grant by the Quebec government that enabled him to go to Paris and study piano with Yves Nat and Mme. Giraud-Latarse. Mathieu also studied harmony and composition with Jacques de la Presle. In December 1936 Mathieu gave a recital of his works at Salle Chopin-Pleyel, and again at Salle Gaveau on 26 March 1939. His recitals as a soloistJean-Pierre Thiollet, 88 notes pour piano solo, Neva Editions, 2015, "Solo nec plus ultra", p. 52. were received very enthusiastically by the Parisian critics. They unanimously agreed that André Mathieu was a "Canadian Mozart".
