St. Louis is uniquely poised to be the hub for modern ragtime — and to learn about the music genre’s historical roots. That’s according to Ethan Leinwand, the co-founder of the St. Louis Ragtime Initiative. Leinwand joins us to talk about ragtime past and present ahead of the monthly Ragtime Rendezvous at the Scott Joplin House. Also joining the conversation is musician Colin Hancock, who will perform with his band “The Oliver-Smith Incomparables” at the Aug. 3 event.