While in high school he organized his first country band, which performed fiddle tunes and US hits of the day, especially those of Jimmie Rodgers. Beattie sang and played harmonica and washboard; the sound of the latter instrument lent a distinctive sound to Beattie's music over the years.
After playing hockey in Western Canada and serving during the Second World War, Beattie returned in 1948 to Arnprior and began performing professionally. With his old-time music group, the Ottawa Valley Melodiers, he was heard regularly on CFRA radio, Ottawa, until the late 1950s and on CHOV, Pembroke, until the early 1960s. He also performed at local fairs, dances, and clubs. The Melodiers included at various times Beattie's daughter Bonnie, the steel guitarist Garnet Scheel, and the noted fiddler Reg Hill.
Beattie's first 78, "The Log Driver's Song," released by Rodeo Records in the early 1950s, was followed by 11 LPs under Rodeo's various labels. Many of his songs were based on Ottawa Valley events, people, and places, e.g., 'Lake Dore Waltz' and 'Train Wreck at Almonte'. Some of his lyrics are included in his autobiography, This Ottawa Valley of Mine (Arnprior 1982).