The mouse symphony here predates Disney's Fantasia by two years, but several studios had been doing shorts that mimicked the Disney series Silly Symphonies.
Released at a time when science fiction and evil inventors were a common theme in entertainment. The splendid attention to detail in the lab here gives a slightly macabre feel to the otherwise humorous action.
The Production Code at the time required a wedding, even for mice. The mice here take their vows in a novel way, by playing a horn.
Dr. I.M Nutts is a play on "I am nuts", or "I'm nuts".
Both Johnny Mouse and the evil cat break the fourth wall, an early example of what would become a WB cartoon standard.