"A Night at the Opera" starts with a restaurant where Mrs Claypool (Margaret Dumont) is sitting down for dinner, but her date is a no show. So she asks the waiter to page him, Otis B Driftwood (Groucho Marx), in which he ends up right behind her. She ends up interested in investing a large sum of money into the New York Opera Company, and they are looking for Lasparri (Walter Woolf King). Lasparir's assistent, Tomasso (Harpo Marx) gets fired right after he meets up with old friend, Fiorello (Chico Marx). Up and coming opera singer Ricardo Baroni (Allan Jones) says goodbye to his girlfriend, Lasparri's leading lady, Rosa Castaldi (Kitty Carlisle) but sneeks abord the ship going over seas with Fiorello and Tomasso in Driftwood's suitcase. They get caught but sneek off the boat disguised as the worlds three most famouse aviators. They get disscovered with Tomasso looses his beard from drinking too much water. Driftwood gets fired from his job and he teams up with Baroni, Tomasso, and Fiorello to kidnap The head of the Opera Company and Lasparri to make Baroni the lead man. They succeed with being cased by the cops the whole time. The crowd loves Baroni more then Lasparri, so the head of the opera company desides, reluctently, to sign him on, under one condition, he and his friends are not arrested.