There are two gags in this short that are commonly called "Disney-swipes." The first involves Foxy deflating the big, fat hippo with a pin which was stolen from "The Opry House" (1929). The second was when Foxy threw a rope around the runaway trolley, wrapped the rope around a pole, held on tight, went spinning around the pole, and was flung back into the trolley.
Listen for the singing hoboes by the side of the interurban line (they sound just like The Revelers).
The title tune was composed in 1931 by Charles O'Flynn and Jack Meskill (lyrics) and Max Rich (music). It was reused in "Who Framed Roger Rabbit?" (1988).
The sequence with the cow over the tracks was previously used in the Oswald the Lucky Rabbit cartoon "Trolley Troubles" (1927)
This cartoon is also included as an extra on the DVD of "The Public Enemy" (1931).
"Smile, Darn Ya, Smile," Music by Max Rich, Lyrics by Jack Meskill and Charles O'Flynn, Sung by Foxy and Roxy, and by the Hoboes;
"Pomp and Circumstance March No. 1," Music by Edward Elgar;
"The Year of Jubilo" and "Good Morning to You," Music by Mildred J. Hill, Lyrics by Patty S. Hill, Sung by Foxy and Roxy