While teaching in London, Welch conducted and administered several small opera companies such as Focus Opera 1963–65, New Circle Opera 1965–66, and Wimbledon Light Opera 1967–68. After moving to Winnipeg in 1969, Welch met S.C. Eckhardt-Gramatté and studied with her until her death in 1974, devoting his musical energies increasingly to composition from that time on. His music is written for acoustical instruments featuring a wide variety of stylistic elements: “Joplinèsque rhythms, aleatoricism, serialism and jazz. He wrote for soloists and all sizes of ensemble.

In Winnipeg, he was choral director of Temple Shalom Synagogue 1970–75, artistic director at the Golden Voices Opera 1970–75, director of the Jewish United Folk Choir 1971–74, musical director of the Cultural Company Choir at Red River Community College 197980, music critic and editor of The Downtowner and The Voice 197989 and for the Winnipeg Sun 198890. A fellow of the American Association of Hypnotherapists, Welch became director of the Winnipeg Hypnosis Centre in 1980. Welch was the winner of the 1990 Folklorama Song Contest, a founding member and president 1982–84 of the Manitoba Composers Association, and a member of the CLComp.