Goofs

Mugs drops the music sheet from his right hand, but in the next shot it's up from the floor and in his left hand.

In the credits, Bobby Stone is billed as playing "Dave," Bill Bates is billed as playing "Sleepy," and Billy Benedict is billed as playing "Benny." In actuality, Stone plays the role of "Rocky," and it's Bates who plays "Dave" (a character who is, indeed, defined by his sleepiness). Benedict indeed plays Benny, but several times he's called "Skinny," his character name in other movies.

Mugs comments on the emptiness of a room, naming knickknacks among the lack of items. He says this near a bookshelf full of books and knickknacks.