Act One
Count Almaviva has hired a troupe of musicians to serenade Rosina at dawn. However, in his attempt to conquer the unknown beauty with whom he has fallen in love from afar, he encounters circumstances that are far from favourable: Dr Bartolo, Rosina’s guardian, has locked the young woman for fear of losing her – and above all her fortune.

Figaro, barber and general factotum, appears at this point. Almaviva recognises him as a former servant and confides his plans to him. Fortunately, Figaro is very familiar with what is going on at Dr Bartolo’s – for time is short: Almaviva and Figaro witness Bartolo leaving the house to tie up his marriage to Rosina this very day. Almaviva serenades Rosina once again, now introducing himself as the poor student Lindoro – because he wants to be loved for his own sake rather than for his lofty social position. Rosina is enchanted.

Egged on by the prospect of payment, Figaro is more than willing to help Almaviva, and comes up with an idea on the spot: disguised as a soldier, Almaviva should seek accommodation in Bartolo’s house.

Rosina turns out to be a self-confident young woman who is determined to escape her prison together with Lindoro; she immediately writes him a letter. At Almaviva’s behest, Figaro is about to test the waters with Rosina, but is prevented from doing so by Bartolo’s return.

Don Basilio, Rosina’s music teacher and a friend of Bartolo’s, tells him that Almaviva is in situ; both suspect that he is a secret admirer of Rosina’s. To oust him, Basilio suggests launching a large-scale smear campaign, but Bartolo wants to draft the marriage contract first.

Figaro tells Rosina that the very enamoured Lindoro is on his way to her. Much to Figaro’s astonishment, Rosina hands him the letter that she has already written to Lindoro.

Bartolo becomes even more suspicious when he notices ink stains and the fact that a sheet of paper is missing.

Disguised as a drunken soldier, Almaviva raucously demands to be quartered at Bartolo’s house for the night. Even Bartolo producing a letter exempting him from the obligation to provide accommodation for soldiers fails to discourage him. Almaviva manages to reveal his identity as Lindoro to Rosina and to pass her a message before Bartolo can intervene. The ensuing quarrel becomes so tumultuous that watchmen appear to arrest the troublemaker. Almaviva, however, identifies himself as a count – and the watchmen have no choice but to put a good face on the matter.

Act Two
Bartolo suspects the drunken soldier, whom nobody knows in the regiment, of being an envoy of Count Almaviva.

The Count himself soon appears, this time disguised as the music teacher Alonso, who is allegedly substituting for Basilio, who has fallen ill. In order to gain Bartolo’s trust, the Count comes up with a lie on the spot: he gives Bartolo a love letter written by Rosina, which he claims to have found with another of Count Almaviva’s lovers, proving that the Count is merely playing games with Rosina.

Rosina immediately recognises the student Lindoro in Alonso. The two of them find an opportunity to declare their love for one another.

Figaro appears, claiming that he can only shave Bartolo today. By deftly causing a distraction, Figaro manages to pilfer the key required for Rosina’s planned abduction.

At that moment, the supposedly seriously ill Basilio enters. By joining forces – and with a little hush money, of course – Almaviva, Rosina, Figaro as well as Bartolo, who believes he has been initiated in the proceedings, succeed in getting rid of the “sick man.”

While Bartolo is being shaven by Figaro, Almaviva and Rosina confer on their escape plan. Bartolo, however, overhears the decisive watchword and flies into a rage – he has been duped yet again. Now he intends to get the job done properly and despatches Basilio to the notary.

Rosina now has to recognise her lover’s ostensible dishonesty: Bartolo presents her with the letter she had written, which the supposed music teacher had slipped to her. At that, Rosina agrees to marry Bartolo and reveals the escape plan.

A violent storm breaks.

Almaviva and Figaro enter Bartolo’s house. At first, Rosina refuses to be carried off by the treacherous Lindoro, the Count’s supposed envoy. Only when the Count reveals his true identity does she acquiesce.

The notary and Basilio, both in fact summoned by Bartolo, are bribed without further ado and sign the marriage contract between Rosina and Almaviva. Bartolo arrives too late and has to content himself with Rosina’s dowry.