I'm drawing some comics about Dolores Gray this week and was researching Carnival in Flanders. Broadwayworld had a post on it this month but there were few details. Kevin Mandelbaum wrote that the score was better than the book. Were there any songs of note beyond "Here's That Rainy Day?"
ibdb lists these as the other songs in the score (I've not heard of any of them):
Ring the Bell The Very Necessary You It's a Fine Old Institution I'm One of Your Admirers The Plundering of the Town The Stronger Sex The Sudden Thrill It's an Old Spanish Custom A Seventeen Gun Salute You're Dead! Take the Word of a Gentleman The Carnival Ballet (Dance) A Moment of Your Love How Far Can a Lady Go?