I think there was much more early jazz on those cartoon soundtracks than classical music. Disney's Fantasia was an exception to the rule, not the rule.

My favorite radio station, WWOZ in New Orleans, plays a lot of jazz from all periods of history. Most weekdays, the mid-morning hours are devoted to some of the earliest recorded jazz, and a lot of that music is very reminiscent of the older cartoons I watched on black-and-white TV as a child in the 1950s.

It often very difficult for me to listen without picturing barn animals running away from Farmer Brown, or a nightclub full of little black mice with big white eyes dancing the night away.