The prologue begins with Carlo Broschi, the famous castrato Farinelli, reminiscing about his childhood as a singer in the church choir. A newly castrated boy runs in and warns Carlo to stop singing, warning that his voice will result in death, before killing himself. Carlo is traumatized and confused by this that he is then unwilling to sing a composition made by his brother Riccardo when told to by his voice teacher, Nicola Porpora later during his voice lessons. He cries and runs off asking why the castrato had to die. Carlo's father comforts him, and makes him promise that he will never refuse his voice to his brother ever again.
The film opens in Madrid, Spain, at the palace of King Philip V. Riccardo Broschi (Enrico Lo Verso) demands to see his younger brother, the Italian castrato Carlo Broschi (Stefano Dionisi), better known by his nickname, Farinelli. Carlo doesn't acknowledge him.
The rest of the film is told in flashback. Eighteen years earlier, Carlo and Riccardo watched as an itinerant trumpet player humiliated a young castrato. Angered, Carlo humiliates the trumpeter in turn. The crowd gives Carlo the nickname "Farinelli". In the crowd there is a pretty lady that Riccardo approaches in order to seduce her, using his brother as "bait". In a nearby tent, Carlo begins to make love to the woman and then Riccardo steps in to complete the act. Meanwhile, George Frideric Händel (Jeroen Krabbé) has heard Farinelli sing from his carriage. He asks Carlo to come to England and perform, but Riccardo demands to be included. Handel sneers at Riccardo as a hack, and humiliates Carlo as a freak, leaving Carlo despondent and Riccardo angry.
Several years pass, and Carlo is now famous. He even impresses the Comtesse Mauer (Marianne Basler), a beautiful and rich young woman more interested in books than opera. The brothers maintain their sexual accommodation: Carlo seduces the comtesse´s maid, but Riccardo consummates the sex act, but refuses to engage in a sexual relationship or to sing for the comtesse. Carlo receives a letter from Handel, who says he intends to hear Carlo sing in Dresden. Before arriving, Carlo suddenly falls ill with a fever. While he is ill, Riccardo tells him the story Carlo has always believed about how he became a castrato—that he had been injured in a fall from a horse, making the castration surgery necessary to save his life. In Dresden, Handel meets with Carlo just before the curtain rises, and tells him the King of England wants him to sing. Unnerved by Handel's offer, Carlo faints on stage. A self-satisfied Handel leaves, leaving Carlo waiting for him in vain.
Carlo is soon thereafter contacted by the young Alexandra Harris (Elsa Zylberstein), and asked to come to London. Handel's Covent Garden opera house is bankrupting the nearby Nobles Theatre, which is run by Carlo's old vocal teacher, Nicola Porpora (Omero Antonutti). Carlo and Riccardo journey to London. Carlo meets Margareth Hunter (Caroline Cellier), and Benedict (Renaud du Peloux de Saint Romain), Margareth's crippled son. Carlo begins to take an interest on Margareth, and dotes on Benedict. However, when Carlo proposed to Margareth, she refuses, out of respect for her late husband. Carlo begins to feel empty and realizes that Riccardo's compositions are full of ornaments and lacking true artistry, he begins to covet Haendel's operas and tries to impress him, but Alexandra, who is in love with Carlo, steals some of Handel's music for Carlo to perform. Riccardo's music is vastly inferior to Handel's, and the relationship between the two brothers deteriorates. Searching his house for his stolen music, Handel hears Riccardo composing. He confronts Riccardo, insinuating that the composer would be better off without Farinelli. Beguiled by Handel, Riccardo reveals (in a flashback-within-a-flashback) that Carlo was a superb singer as a child, and when their father died, Carlo was seriously ill, the fear of losing that voice prompted him to drug Carlo, tell him a story of how he fell off a horse and castrated him illegally, and to soothe himfor his loss, Riccardo would compose the greatest opera for Carlo to sing: "Orpheus".
That evening, Handel meets with Farinelli backstage. He tells Farinelli the secret of his castration and allowing him to sing his stolen music. Heartbroken by this revelation, Carlo sings Handel's music (the aria Lascia ch'io pianga ) so beautifully that Handel faints.
The flashback ends. The audience learns that Carlo fled from Riccardo with Alexandra to the court of Spain, and has not sung in public since his triumph at the Nobles Theater three years earlier. Carlo has never forgiven Riccardo for castrating him, but Alexandra, who understand the bond between the brothers, tries to reconcile them, she steals "Orpheus", the opera that Riccardo promised Carlo to create. Carlo recognizes that the opera is the best masterpiece ever written by Riccardo, something he longed for, however he hasn't forgiven him. Carlo sings for King Philip during a solar eclipse. Overwhelmed by the pain of his guilt and the broken relationship with his brother, Riccardo slashes his wrist in a suicide attempt as he listens to Carlo sing during the solar eclipse. After falling unconscious from blood loss, he is brought to the house Carlo and Alexandra share, where he recovers. Carlo, realizing that there is no greater atonement for his brother's actions, forgives Riccardo for castrating him. Together, the brothers make love to Alexandra.
Some months pass. Alexandra is now pregnant with Riccardo's child, which Carlo and Alexandra treat as their own. The film ends as Riccardo leaves Madrid to seek his fortune as a composer, taking comfort in the fact that in leaving Carlo with a child to father, he has given his brother back his "share of humanity."
Although Dionisi provided the speaking voice (originally in French), Farinelli's singing voice was provided by the Polish soprano, Ewa Malas-Godlewska and a countertenor, Derek Lee Ragin, who were recorded separately then digitally merged to recreate the sound of a castrato. Its musical director was the French harpsichordist and conductor Christophe Rousset. The musical recording was made at the concert hall, the Arsenal in Metz, with the orchestra Les Talens Lyriques.
The movie is not dubbed into English; it is spoken in French and Italian, with subtitles. This matches fairly well the actual situation at the time, when French was the lingua franca of Europe, much as English is throughout the world today, and most letters, commentaries, official documents and books were written in that language, even well beyond the borders of France. In many scenes, Riccardo Broschi speaks to his brother in Italian, while Carlo replies in French; also, the English court visiting the Covent Garden Theatre speaks in French to the actors and composers, and that also is fairly acceptable from an historical standpoint.
The plot is completely fictional. Although based on real-life events, the film took dramatic license with the basic facts of Farinelli's life. The relationship between the Broschi brothers (including their sexual exploits), the rivalry with Handel, and Farinelli "rock star" fame are spurious. Riccardo Broschi had much less importance in Farinelli's career than is depicted in the film, while Porpora's influence (and that of other composers of the Neapolitan School) is de-emphasized. The movie also offers a different explanation for how Carlo came to take the stage name Farinelli than has been historically ascertained.
Although settings, scenery, costumes and props are historically accurate, the producers took many liberties with the physical appearances of the characters. According to some critics, the actors did not look like the Broschi brothers, and the actors were given modern hairstyles and retained modern mannerisms. Nicola Porpora's disheveled and scruffy appearance is historically inaccurate, and more appropriate for a commoner of the era than a wealthy and distinguished composer. Additionally, few actors are depicted wearing wigs, which was practically mandatory for the main characters (given their social status).
Farinelli was released in 1994 and won the Golden Globe for Best Foreign Language Film in 1995. It was also nominated for an Academy Award in the same category.
The film was given an "R" rating by the MPAA due to depictions of adult themes and sexuality. The movie is available on a Region 1 DVD with a spoken track in French and Italian with a little English, and English and Spanish subtitles. A director's cut blu-ray edition was released in France, Italy, and South Korea, but all of them lack English subtitles. The Korean version also includes a DVD-Audio 2.0 disc.