By the end of World War II, "mountaineer" string band music known as bluegrass had emerged when Bill Monroe joined with Lester Flatt and Earl Scruggs, introduced by Roy Acuff at the Grand Ole Opry. That was the ordination of bluegrass music and how Bill Monroe became to be known as the "Father of Country Music." Gospel music, too, remained a popular component of bluegrass and other sorts of country music. Red Foley, the biggest country star following World War II, had one of the first million-selling gospel hits ("Peace in the Valley") and also sang boogie, blues and rockabilly. In the post-war period, country music was called "folk" in the trades, and "hillbilly" within the industry. In 1944, The Billboard replaced the term "hillbilly" with "folk songs and blues," and switched to "country" or "country and Western" in 1949.
1958 saw its first Canadian rock and roll teen idol Paul Anka, who went to New York City where he auditioned for ABC with the song "Diana". This song brought Anka instant stardom as it reached number one on the US Billboard charts. "Diana" has gone on to be one of the best selling 45s in music history. US-born rockabilly pioneer Ronnie Hawkins moved to Canada in 1958, where he became a key player in the Canadian blues and rock scene. The 4th of October was declared "Ronnie Hawkins Day" by the city of Toronto when Hawkins was inducted into Canada's Walk of Fame. He was also inducted into the Canadian Music Industry Hall of Fame and his pioneering contribution to rockabilly has been recognized with induction into the Rockabilly Hall of Fame. https://www.youtube.com/watch?v=gtKVuwDQUl0