In his only opera, ''Fidelio'', [[Music/LudwigVanBeethoven Beethoven]] made use of two themes dear to him: freedom, and the concept of the spiritually ideal woman.

The opera has a troubled history. The first version, a three-acter called ''Leonore'', was poorly received. Indeed, people who have seen the infrequent revivals are often struck by how relentlessly gloomy it is. Beethoven took the opera back, drastically revised it, and re-cast it in two acts (the second act is very short). The final version, ''Fidelio'', still has its share of problems regarding its dramatic structure, but hey, it is Beethoven, and the music is what counts.

Marzelline, daughter of the old jailer Rocco, has eyes on the new boy Fidelio, and is trying to repel the tenacious advances of another young jailer, Jaquino. Fidelio, on his side, works extra hard to earn the trust of Rocco. Rocco gets the wrong message, and generally approves of his daughter's choice -- none knows that Fidelio is actually a woman called Leonore, disguised to rescue her wrongfully imprisoned husband Florestan. The four Mazelline, Rocco, Jaquino, Fidelio sing the famous canonic quartet: Mazelline and Rocco fantasize the happy days ahead; Jaquino grumbles at being hopeless against the competition; and Leonore/Fidelio worries that her cover might be blown.

As Jaquino leaves, Rocco gets frank with Fidelio: If you want a life, you've got to have money. Leonore feels awkward, but nonetheless sensing the time is right, so she ventures the question she longs to ask: Who is the prisoner in that super secret dungeon that only Rocco is allowed in? "Oh, you don't want to know: wretched chap there wasting away for two years. Pretty horrid sight." Fidelio assures him that ThePowerOfLove will grant her courage.

Don Pizarro, governor of the prison, summons Rocco for a little side order: the minister will have a surprise visit to the prison the next day, and a certain prisoner needs to be silenced. Despite the offer of money, Rocco refuses to get his hands dirty, but consents to digging the grave for the poor chap Florestan. Fidelio hears this, and her resolve strengthens.

Meanwhile, to facilitate her search, Fidelio has persuaded Rocco to let the prisoners to roam the prison yard, ostensibly to enjoy a day in the sun. Pizarro, furious, orders all the prisoners back in their cells. Fidelio fails to find Florestan.

Act II can be readily summarized: Florestan, in his dirty dank dungeon, laments how his righteousness and honesty has been thus rewarded. Rocco and Fidelio finds him more dead than alive. Fidelio recognises him, and offers him as much comfort as she can without blowing her cover. When the grave is ready, Rocco signals Pizarro. Pizarro [[EvilGloating gloats]] over Florestan. Fidelio reveals her true identity "Kill me first; I am his wife." and points a pistol at Pizarro. At that moment, a trumpet announces the arrival of Don Fernando, the righteous minister of the King. Pizarro is arrested, and all his prisoners are set free. Cue [[CrowningMusicOfAwesome Choral Music of Awesome]] as the crowd cheers for the brave, faithful woman who saves her husband.
!! ''Fidelio'' contains examples of:
* CharacterFilibuster -- Don Fernando: ''I detest grim tyranny. I see every man as my brother''. He does not have much stage time, to be sure, but is distracting in his blatantness.
* [[CounterpointDuet Counterpoint Song]] -- the "Canonic" quartet.
* [[DistressedDude Dude in Distress]] Florestan.
* EvilGloating -- Pizarro lives for this. The [[PrepareToDie "Prepare to Die!"]] speech sounds marginally better in German delivered by a baritone.
* HellholePrison
* JustInTime -- Don Fernando's last-minute jail bust.
* LoveTriangle -- Jaquino-Marzelline-Fidelio. It goes nowhere.
* MeaningfulName -- Fidelio, fidelity. No subtlety here.
* MoneySong -- Rocco's "Hat man nicht auch Gold beineben" ("If you don't have money on the side")
* RoundedCharacter -- any half-decent Rocco should be able to steal the show: after all, Rocco is the only character in the cast that is not a [[FlatCharacter cardboard cutout]]
** Arguably because he's the nearest there is to an [[AudienceSurrogate Audience Surrogate]]. He has a conscience, he doesn't like the way Pizarro treats his prisoners and certainly doesn't like the idea of killing anyone, but he's got a job to do and he wants to make sure his daughter is cared for. A good Rocco ought to make the audience feel a little uncomfortable about what ''they'' would do if they lived under a tyrant like Pizarro.
** Arguably also because this is an opera and Rocco doesn't get the best opportunities to shine from a musical point of view.
* SweetOnPollyOliver -- Marzelline on Fidelio.
* VillainSong -- Pizarro's "Ha! Welch' ein Augenblick!" ("Ha! What a moment!") is a [[CrowningMusicOfAwesome truly magnificent]] example. He even begins with he words Ha! Ha! Ha! if there were any doubt as to how villainous he is...
* ViolentlyProtectiveGirlfriend -- PluckyGirl Leonore [[SweetPollyOliver disguises herself as a boy named Fidelio]] to release her unjustly jailed husband Florestan from prison. At some point, she threatens BigBad Pizarro to protect him.
* VoiceTypes:
** Sopranos -- Fidelio and Marzelline
** Tenors -- Jaquino and Florestan, one a [[TenorBoy genuine ingenue]], the other a goody-two-shoes.
** Bass Baritones/Basses -- Pizarro, because EvilSoundsDeep; Rocco, the closest to a ''buffo'' role in this opera; and Fernando.