Possible Clues:

• Rudy with a megaphone
• Crooner with a megaphone
• One of the first crooners
• Rudy --, American singer who appeared in the 1929 film 'The Vagabond Lover'
• Crooner Rudy
• Singer Rudy
• Leader of the Connecticut Yankees in 1920's-40's music
• 'Vagabond Lover' singer