Despite the common image of Bing Crosby crooning alone at the microphone, he was an eager and prolific collaborator. He trades laidback jibes with Louis Armstrong on “Gone Fishin'”, salutes big bands with Al Jolson on “Alexander's Ragtime Band” and anticipates the winning of World War II with The Andrews Sisters on “Victory Polka”. He even plays host to Groucho Marx on “Lydia the Tattooed Lady”.