What a great Columbia cartoon! Hot jazz with a galloping "St Louis Blues" vocal at the end. This was a big surprise after suffering some pretty lame Columbia cartoons for their 1936 offerings.
Can't be well known as Scrappy gets a credit. It's a Color Rhapsody with no trace of Scrappy! These Columbias brought to us by a great guy deeply involved in cartoons, in UK these things likely never seen since released, if ever shown perhaps.
The band is likely Cab Calloway with his hot sound, an unknown (to me) female vocalist sings St Louis Blues, would be great to find out who, as it's not the 1930 hit version with Cab singing.
