Ariadne auf Naxos is in two parts, called the Prologue and the Opera. The first part shows the backstage circumstances leading up to the second part, which is in fact an opera within an opera.
At the home of the richest man in Vienna, preparations for an evening of music are under way. Two troupes of musicians and singers have arrived. One is a burlesque group, led by the saucy comedienne Zerbinetta. The other is an opera company, who will present an opera seria, Ariadne auf Naxos, the work of the Composer. Members of the two companies quarrel over which performance should be presented first. However, the preparations are thrown into confusion by an announcement by the Major-domo. The dinner for the assembled guests has run longer than planned. Therefore, both performances must take place at the same time as they have been ordered and paid for. The performances must not run one minute later than scheduled, despite the late start, since at nine o'clock there will be fireworks in the garden.
At first, the impetuous young Composer refuses to discuss any changes to his opera. But his teacher, the Music Master, points out that his pay depends on accepting the situation, and counsels him to be prudent, and Zerbinetta turns the full force of her charm on him, so he drops his objections. The cast of the opera seria intrigue against each other, each demanding that his arias be not cut while the other performers' parts are cut instead. A dancing master introduces Zerbinetta into the plot, which she understands from her very own perspective, and she gets ready for the performance. The Composer realizes what he has assented to, plunges into despair and storms out.
Ariadne auf Naxos at the Hamburg State Opera 2012: the thespians attempt to cheer up Ariadne
Ariadne is shown abandoned by her former lover, Theseus, on the desert island of Naxos, with no company other than the nymphs Naiad, Dryad, and Echo. Ariadne bewails her fate, mourns her lost love, and longs for death. Zerbinetta and her four companions from the burlesque group enter and attempt to cheer Ariadne by singing and dancing, but without success. In a sustained and dazzling piece of coloratura singing, Zerbinetta tells the Princess to let bygones be bygones and insists that the simplest way to get over a broken heart is to find another man. In a comic interlude, each of the clowns pursues Zerbinetta. Eventually, she chooses Harlequin, a baritone, and the two sing a love duet together while the other clowns express frustration and envy.
The nymphs announce the arrival of a stranger on the island. Ariadne thinks it is Hermes, the messenger of death, but it is the god Bacchus, who is fleeing from the sorceress Circe. At first they do not understand their mistaken identification of each other. Bacchus eventually falls in love with Ariadne, who agrees to follow him to the realm of death to search for Theseus. Bacchus promises to set her in the heavens as a constellation. Zerbinetta returns briefly to repeat her philosophy of love: when a new love arrives, one has no choice but to yield. The opera ends with a passionate duet sung by Ariadne and Bacchus.