When Moe gives Shemp a piece of banana to make him swallow the sleeping pill, his mouth is closed, but in the next shot, it is open again.
A line that Shemp was about to say is cut off when Moe tells him to keep practicing.
When Shemp unintentionally smashes his own fingers on the piano, the severed fingers still playing the notes range from up and down the musical scale.
When the Stooges crawl of the phone booth, Vernon Dent is seen sticking his head out of the panel that was previously covered in glass.
Vernon Dent's shadow on the wall is visible too early when the Stooges crash into it, mistaking it for an actual window.