Born in Andria in a wealthy family, his father Salvatore, who held administrative feudal duties, was a great music lover and wanted to address both his sons to professions in the sector, making Riccardo, the elder, a composer and Carlo as a singer. It was his brother Riccardo who wanted castration for Carlo, performed shortly after his father's death in 1717. Castration is a surgical operation that allows males to retain their soprano or contralto voice before development can modify it. . It should be noted that, depending on the mode of the surgical operation to which they were subjected, the castrati could have a partial sexual development, and therefore also develop a partial mutation of the voice.
The young man was sent to Naples to study singing with Niccolò Porpora who took care of the refinement of his natural talent as a soprano. His debut took place in Naples, in 1720, in the serenade "Angelica e Medoro" (of Porpora), alongside Marianna Benti Bulgarelli, known as Romanina, Domenico Gizzi, Musico Soprano of Real Cappella and Contralto Francesco Vitale, in a soirée in honor of the Empress of Austria. The libretto was the first theatrical performance of Pietro Metastasio, who held a friendship with Broschi that lasted a lifetime and is testified by an interesting correspondence. He recovered a great success and the subsequent performances earned him a growing rapid notoriety.
In the Carnival season of 1722 he made his debut in theater in Rome, singing, in the Alibert Theater, in the drama for music "Sofonisba" of the Bolognese Luca Antonio Predieri and in "Flavio Anicio Olibrio" of Porpora, again alongside Domenico Gizzi and by Francesco Vitale. In 1723 and 1724 he was again in Rome for the triumphal Carnival Stages, again at the Alibert Theater, in dramatic productions of absolute prestige: "Adelaide" by Nicola Porpora in 1723 and "Farnace" by Leonardo Vinci in 1724, always alongside Gizzi. In the following years he sang in Rome, Vienna, Venice, Milan, Bologna.
The public of the time adored the virtuosity, which in the singers consisted above all in the execution of arbitrary variations to the sung pieces, in which the aspect of extreme technical difficulty enriched the pure expression of the feelings of the music. There were also frequent "duels" between musicians. If in Rome Broschi had won (1722) a challenge against a German trumpet player, on the long held of a very high note, in Bologna (1727) the competition arose with Antonio Maria Bernacchi, then one of the most important castrati of the music scene. In fact, in addition to the spectacular forcing, there was no personal antagonism between the two, so much so that Bernacchi himself, about twenty years older, was very generous with advice and suggestions to the young Pugliese. Already in Naples in 1725 it was noted by Johann Joachim Quantz on the occasion of the first performance of Marc'Antonio and Cleopatra di Hasse; Quantz who had enthusiastically magnified the purity of timbre and extension of scale, the sharpness of trill and inventiveness. The victory over Bernacchi, however, greatly increased the fame of Broschi, whose activity became (to measure the times) somewhat hectic.
In 1730 Farinelli was admitted to the Bologna Philharmonic Academy. In 1734, Carlo Broschi moved to London and sang at the Opera della Nobiltà at Lincoln's Inn Fields, which was conducted by Porpora and saw Francesco Bernardi, known as the Senesino, as the lead singer. His fame was immense, and the proceeds he earned in the three years he stayed in England exceeded £ 5,000. These years, the peak of his glory as a stage artist, were also the years of the burning rivalry between the two theater groups residing in London, that of Georg Friedrich Händel, supported by King George II, and that of Porpora, supported by the Prince of Wales and nobility.
The first appearance at the Lincoln's Inn Fields theater was in Artaxerxes, most of whose music was written by his brother, Riccardo Broschi. Success was instantaneous. Frederick Prince of Wales and the court welcomed him with praise and honors. But even the contribution of Farinelli led the company to success.
In 1737, tired of the incessant bitterness that opposed the two theatrical groups, Farinelli accepted the invitation of Elisabetta Farnese, wife of Philip V of Spain. During the journey he passed through France, and sang for Louis XV. The Spanish king, who suffered from neurasthenia and melancholy, had abandoned public life, affairs of state and showed signs of madness. Queen Isabella then invited Farinelli to perform in front of her husband, in the hope that he might awaken him from apathy. The episode remained famous, and helped to increase the legend surrounding the singer. Farinelli's voice had such an effect on Filippo V, who no longer wanted to separate himself from the singer. The daily "therapy" consisted in making the castrato always sing the same eight or nine arias, of which the first was "Pale the sun", by the Arsaserse of Johann Adolf Hasse. From a room different from that of the sovereign, the first times from the farthest room and gradually closer and closer until you get behind the door, the singer managed to get the suffering Filippo out, he had him washed and shaved. The king made him promise to remain at the court of Spain, paying him a salary of 2000 ducats, with the only request not to sing more in public.
Having become familiar with the kings of Spain, the singer saw its importance grow with the ascent to the throne of Ferdinand VI of Spain, who named him a knight of Calatrava, a high office, reserved for gentlemen who could prove the nobility and the antiquities of their families. Broschi-Farinelli, favored by the monarch, exercised on the court, and on politics, a great influence. He was responsible for the first reclamation works on the banks of the Tagus, and directed the work of Madrid and royal shows. He used his power to persuade Ferdinando to set up an Italian opera house. He also collaborated with Domenico Scarlatti, a Neapolitan compatriot, who also resides in Spain. The musicologist Ralph Kirkpatrick states that Farinelli's correspondence is the source of "most of the first-hand information about Scarlatti come to us".
Respected by anyone, submerged in gifts, flattered by both diplomats who are against France, and those who wanted to see Spain signing the Family Pact, retained this important position until the advent of Charles III, who probably due to the excessive influence of the singer, he dismissed it in 1759.
Farinelli then retired to Bologna, and died in the sumptuous villa he had built for his retreat (outside Porta Lame, now destroyed). Despite the numerous visits he received (including those of Wolfgang Amadeus Mozart, then a teenager, and Joseph II of Austria), Farinelli suffered until his death of loneliness and melancholy.
He died on September 16, 1782, a few months after his friend Metastasio, leaving a collection of art and musical instruments unfortunately dispersed by his heirs, including a violin by Antonio Stradivari. Of him there are some beautiful portraits painted by Jacopo Amigoni and Corrado Giaquinto, and the letters to his friends. Despite the legend, it remains a relatively mysterious character. To his friends who asked him to write his memoirs, he replied: "It is enough for me to know that I have had no prejudices against anyone. Add to my regret that I could not do all the good I would have wished for. "