Looking into one guy named Jack Arthur this morning has made me aware of another, so we treat of them both. Neither was the same as Johnny Arthur, who appeared in comedy shorts, btw!
The American Jack Arthur (Arthur E. Campbell, 1900-1980) was billed in his early years as Johnny Hart. He was a singer and emcee, presumably in vaudeville and night clubs, which in the 1930s led to Broadway, films and radio (especially the latter). WOR was one of the stations on which he performed. He was featured in the Ziegfeld Follies of 1931, which led to several film shorts: Poor Little Rich Boy (1932) with Phil Baker, Charles Eaton and the Gale Sisters; Supper at Six (1933), Music and Models (1938), and Projection Room (1939). In 1942 he starred as the title character in the Broadway show Johnny 2 x 4, with George Kelly, and a young Betty Bacall! He was living in Florida when he died in 1980.
The other Jack Arthur was a Toronto-based musician, though he too made his way from vaudeville to mass media (1889-1971). Born in Glasgow, he was a violin-playing child prodigy who played in music halls from age 7, accompanying the likes of Harry Lauder. He moved to Toronto at 13 and studied at the College of Music. He performed in minstrelsy and vaudeville and became musical director for George Primrose. From the late teens through the late ’30s he was musical director at major Toronto theatres; in the mid ’30s he produced shows on Canadian radio. From 1952 through 1967 he produced an annual show at the Canadian National Exhibition in Toronto, called the CNE Grandstand Show. And he hosted a show called Mr. Show Business, which was broadcast on radio 1952-54, and on television 1954-55.
To learn more about vaudeville, which was apparently partial to guys named Jack Arthur, please see No Applause, Just Throw Money: The Book That Made Vaudeville Famous.