Pelletier's first concerts were given as the winner in 1962, 1964, and 1966 of the MSO Matinée auditions. He also performed in recital in 1969 and 1970 in Quebec City and in 1975 and 1976 at the Canadian Cultural Centre in Paris and toured in 1976 in Tunisia. For the JMC (YMC) he toured 1977-8 in Quebec and Ontario, and 1978-9 throughout Canada. He also played at Canada House in London in 1980, for the Washington Music Ensemble in 1986, at the Montepulciano Festival in Italy in 1987 and at the Academy of Arts of Honolulu in 1988. He is an enthusiastic promoter of contemporary music, and his appearances with the SMCQ include a performance as soloist at the Canadian Pavilion during Expo 67; participation in the North American premiere of André Boucourechliev's Archipel III, Montreal 1972; a performance at the 9th International Festival of Contemporary Art in Royan, 1972; and participation in the North American premiere of Luc Ferrari's Société II, Montreal 1975. In 1976 his performance for the SMCQ of the complete piano works of Schoenberg, Berg, and Webern from memory was hailed by the critic Claude Gingras as a 'total success' (Montreal La Presse, 12 Nov 1976). In 1979 he received the grand prize at the fourth international piano competition of the Arnold Schoenberg Festival in Rotterdam.
Among the Canadian works Pelletier has premiered are Michel Vinet's Métamorphose, Raynald Arseneault's Sonata, Michel Gonneville's Contribution à l'étude de phénomènes musicaux (a work he commissioned with a grant from the Canada Council), Claude Vivier's Shiraz, and Michel-Georges Brégent's Trad-sens Concertio with the MSO. With the latter in 1986, he also premiered Musique concertante pour l'embarquement de Cythère by the Belgian composer Claude Ledoux. Besides the MSO, Pelletier has also performed with the Quebec, Nepean Symphony Orchestra (Ont), Vancouver, Kitchener-Waterloo, and Utrecht (Netherlands) SOs, and the Orchestre métropolitain. He has performed on CBC radio and TV as well as on BBC London. The Canadian Music Council named him artist of the year (special mention) in 1980. Following a recital in Pollack Hall, Eric McLean asserted that '... physically, emotionally, and intellectually, he is one of the most complete artists this country has produced' (Montreal Gazette, 17 Feb 1987).