(Film critic Leonard maltin delivers the clue.)"Three Little Pigs", a Disney Silly Symphony of 1933, introduced this song that became an anti-Depression anthem
The 
Tortoise and the Hare became a landmark Disney cartoon because it... [DOC] [TLE] Disney in Concert: A Silly Symphony Celebration - The Film Music ... [PAR] Aug 18, 2015 ... Film historian and Disney expert Leonard Maltin hosted both, which featured a ... 
Maltin introduced them as "the cream of L.A. studio musicians.