In the 40s and 50s, The Adventures of Sam Spade, was a popular US radio show based on stories written by Dashiell Hammett, featuring Howard Duff in the lead. But the story Blue Moon features the the chemistry of Bogie and Bacall!

The Free Information Society has five of the original broadcasts available for free download:

• Blue Moon: with Humphrey Bogart and Lauren Bacall.
• Missing Newshank Caper
• Over My Dead Body Caper
• Stopped Watch Caper
• Terrified Turkey Caper

The Thrilling Detective site has more information on the shows on it’s excellent Sam Spade page.