The boy, who had been born on St Maurice's day, was baptized José Mauricio Nunes Garcia, on December 20, 1767, in the city's cathedral, now the Church of Nossa Senhora do Rosário [pt].

According to Manuel de Araújo Porto Alegre, one of Nunes Garcia's early biographers, the young boy had "a beautiful voice and a sharp musical memory", "reproduced everything he heard", and "created his own melodies and played the harpsichord and the guitar without ever have learned to".

Note: the abbreviation CPM refers to the Thematic Catalogue of Nunes Garcia's Works, compiled by the musicologist Mrs. Cleofe Person de Mattos.

In the 1780s, he studied for the examinations he had to go through to take the holy orders, and developed a musical partnership with the old chapel master and subchanter of the See, deacon João Lopes Ferreira.

From this period are known 32 pieces of music, among them graduals, antiphons, various psalms, a Magnificat (CPM 16) for voices and organ, the vespers Vésperas das Dores de N. Srª.

Some weeks later, another boat brought the information of the precise date of the arrival: March 7, and a request from prince regent John: to assist at a Te Deum, celebrated in the city's See, in thanksgiving for the successful trip.

The admission of the Brazilian priests had been officialized, but the Portuguese clergy thought otherwise: in an anonymous document, they stated that, as a measure of economy, the ministers should be limited to those who previously served the prince regent.

In February 1809, the prince regent, impressed by the improvisations played by Nunes Garcia at the pianoforte in his palace, retrieved a medal from the coat of the baron of Vila Nova and attached it to his garments, making him a knight of the Order of Christ.

This job put him in contact with a more up-to-date repertory, and by studying the scores, he incorporated new techniques to his compositional skills.His salary, although sufficient for him alone, was not enough to face his children's needs for food, education and care.

In this same year, the French army, led by Napoleon Bonaparte, was defeated in Leipzig, and in 1814 Pope Pius VII returned to Rome from his exile in Avignon.

This year Nunes Garcia composed the Moteto para a Ordenação do Ilustre Bispo da Real Capela – Motet for the Ordination of the Illustrious Bishop of the Royal Chapel; the ceremony occurred only on March 15, 1816.

The prince regent, in a gesture of reconciliation with France, and concerned about the development of culture and arts in Brazil, sponsored the travel to Rio of a French artistic mission, with specialists in painting, sculpture, architecture, and historiography.

Neukomm was also responsible for the first presentation in Brazil of Mozart's Requiem (K 626), in the church of the Recolhimento do Parto, with the musicians of the brotherhood of St. Cecilia conducted by Nunes Garcia.

The writings of Porto Alegre which claim that he regarded the Brazilian composer as "one of the greatest improvisers of the world", or that "he admired his self-education in music" are suspicious, because he is not even mentioned in Neukomm's autobiography.

Soon, by request of the prince regent, Nunes Garcia composed the opera Le Due Gemelle, the first work of its kind to be presented in Brazil.

And in this year he composed also the Missa Para a Festa da Degolação de S. João Baptista (CPM 120), – Mass for the Feast of the Beheading of St. John the Baptist, which he completed in 20 days at the Royal Farm.

Marcos Portugal stayed, or was left, in Brazil, not because of his own will, but probably because of his poor health, and in order to continue teaching music to the prince regent Pedro.

Besides his own compositions while he was in Brazil, he made an important contribution to the history of Brazilian music, by putting onto paper some modinhas composed by Joaquim Manoel da Câmera, a popular singer and guitar player of that time.

In this year 1821, Nunes Garcia also composed a Laudamus that recalls the music of Rossini, whose operas were beginning to make success in the theatres of Rio de Janeiro.

The financial difficulties forced the prince to cut the extra benefits that were conceded to the court musicians, including Nunes Garcia, keeping only their full wages.

The priest wrote a letter to the prince, requesting to be restored the extra benefit conceded by King John VI, justifying it as a payment for his public music teaching.

The prince regent Pedro, facing local upheavals, and in order to avoid the country being split into smaller republics, such as had happened in the Spanish Americas, on his way to the province of São Paulo, decided to declare the Brazilian independence of Portugal on September 7, 1822.

It is a monumental piece of music (some 276 pages long), and the score was later donated by his son Dr. José Mauricio Nunes Garcia as an admission fee to join the Brazilian Historical and Geographical Institute.

He embarked to England, to assemble a fleet to fight against his brother Miguel, who threatened to usurp the Portuguese throne of his daughter Maria da Glória.

He made precise copies of many of his works, creating a personal file that was later acquired from their heirs by the Brazilian government, and is now in the School of Music of the Federal University of Rio de Janeiro.

Taunay wrote many articles and texts about the composer, and after he was elected to the house of the representatives in 1881, he presented in 1882 an act intended to trace all of Nunes Garcia's works, which was not approved.

Mattos wrote and had it published by the Federal Council of Culture, in 1970, a Thematic Catalogue of Nunes Garcia's works, where she analyses in detail all of his remaining scores.

And finally in 1997, she published the book José Mauricio Nunes Garcia – Biografia, in which, despite her emotional treatment of the hardships the composer passed through, many events of his life, before obscure, have been made clear.

In two of these payrolls there are records of pay bills to Nunes Garcia, up to the annual sum of R$625000 (six hundred twenty-five thousand réis) – about USD 20,000 in present money – that was his income from 1822 to 1830.

On June 18, 2023, Nunes Garcia's Requiem had its Carnegie Hall premiere under the baton of Mark A. Boyle (Director of Choral and Vocal Activities at Seton Hill University, conducting the New England Symphonic Ensemble and a festival chorus of 135 voices.