Irish-born American tenor John McCormack, who sang both popular and classical works, was one of the most successful live musical performers of the 1910s, 1920s, and 1930s, regularly selling out concerts in the biggest halls around the world, as well as being a top recording artist. The 600-plus sides he recorded, primarily for Victor Records, between 1904 and 1942 are estimated to have sold upward of 200 million copies. Chart researcher Joel Whitburn, in his book of chart approximations, Pop Memories 1890-1954, ranks McCormack 23rd among the top artists of the 64-year period, ...