In 1769-1772 the young Johann Simon was sent to study at the monastery of Weltenburg, in Mendorf. His musical talent struck a “remarkable person in Vienna” who offered to host him in the devoted to music capital of the Hapsburgic Empire, Mayr will recall years later. His father did not agree. However, thanks to his talent for singing, in 1773 Mayr was entitled to a scholarship in the Jesuit College in Ingolstadt, where he studied “grammar, rhetoric, logic and physic”. In 1777 he was admitted to the university where he “dedicated himself to the study of law”. In this environment he will get to know the Baron de Bassus, who in the meanwhile had become the owner of the Mendorf feud and who will take him under his wing.
The Bassis were a prominent family in Poschiavo, administrative center of the independent Grey league, within the Three Leagues state. In 1675 they had inherited the Signoria in Mendorf and in Sandersdorf, in Bavaria: later on they acquired other titles and their surname had been ennobled and turned in De Bassus. Dead without having heirs, in 1780 properties and titles had been inherited by Thomas Franz Maria (1742-1815), who was already podestà in 1767 and in 1775 in his native Poschiavo.
De Bassus, a student of Adam Weishaupt (1748-1830), professor of Right at the University of Ingolstadt, in 1778 De Bassus had joined the Illuminati, a secret society founded in Weishaupt in 1776, of masonic origin but definitely more radical.
In 1784 the Bavarian authorities grew intolerant towards the Illuminati. On his way back from Poschiavo, where he had been entitled podestà again in 1785, De Bassus hosted them in his castle in Sandersdorf, which had been searched by police and documents sequestered. The following year Illuminati were declared outlaw: De Bassus left Bavaria and took cover in Poschiavo.
Mayr followed him, and for a couple of years since 1786 (or 1787) they will be together in Sandersdorf, then in Poschiavo and in Tirano. He had started again his studies as an autodidact, and he had even published a collection of German songs (1786). De Bassus not only encouraged him, but he also financiered his studies.
Giuseppe Ambrosini from Bergamo was operating in Poschiavo between 1780 and 1787, husband to a cousin of the baron, responsible of a publishing house sponsored by De Bassus with the purpose of diffusing non-orthodox books in Italian. It is likely that through Ambrosini, Mayr got to know Carlo Lenzi (1735-1805), maestro in S. Maria Maggiore since 1767, and decided to study with him in Bergamo. The experience is a deluding one, and the economic support by De Bassus is about to extinguish. Mayr managed to find another patron in Bergamo, the canonical count Vincenzo Pesenti (1720c.-94), who had hired him and financed his studies in Venice with Ferdinando Bertoni (1725-1813), maestro di cappella in St Mark.
Mayr’s education was prompted by his intense studies and what the rich music environment in Venice offered, more than by his relationship with Bertoni. The city offered a wide range of religious music, theatrical works, concerts in Conservatories. Mayr himself began to present his own works: church music (1791) and four oratoris at the Conservatorio dei Mendicanti between 1791 and 1795. During carnival 1794 he made his debut at the Fenice with the opera seria Saffo, which was not really successful. The support by the renown Niccolò Piccinni (1728-1800), who was in Venice for theatrical engagements, and the death of his patron Pesenti, in December 1794, lead Mayr towards a theatrical career.
As a composer at the service of a noble protector, Mayr was now a freelance in the field of the Italian theatre. He was more and more present in the programs of Venice theatres with opera seria, comic opera and farce, he gained the first successes at the Fenice with the drama Lodoiska (1796) and in S. Benedetto with the farce Che originali! (1798).
In November 1796 he married Angela Venturali, to whom he had given private lessons since 1790. The girl is 27 years old and comes from a wealthy familiar background, the daughter of a merchant whose house was in Calle della Rosa in Venice, and who had a country villa in Villorba, by Treviso. One year after the wedding, she died in childbirth giving life to Giuseppe, who survived for just a few weeks.
The career of Mayr had now begun. During the Napoleon siege in Italy, he composed for the Scala (1899), he inaugurated the theatre in Trieste (Ginevra di Scozia, 1801), he worked in Naples, Roma, Vienna (1802-03). In May 1802 he was nominated maestro di cappella in S. Maria Maggiore in Bergamo, replacing Lenzi. The president of the institution administrating the cappella was an acquaintance of Mayr, met in Poschiavo, i.e. Giuseppe Ambrosioni.
Mayr moved definitely in Bergamo, and in 1803 he bought a house in contrada S. Lorenzino 151 (today Via Mayr). In October 1804 he will marry his sister-in-law Lucrezia Venturali, with whom he will have Giuseppe, who didn’t survive longer than a couple of months (1809), and Marietta (1812-69). Marietta married the engineer Luigi Massinelli in 1837, and she will give Mayr a granddaughter, Adele (1838-1921).
Mayr’s theatrical career will continue until 1824, in the most important theatres in Milan, Naples, Venice, Rome.
Just to stay in Bergamo, his adoptive homeland, Mayr refused a prestigious work in Vienna (1802), in Paris at the Napoleonic court (1805), in Milan as director of the Conservatory (1807), Dresda (1808).
Once left the theatrical profession, Mayr continued the profession of maestro di cappella in S. Maria Magiore. He was also the official composer during public events, such as when the emperors of Austria Francesco I (1816) and Ferdinando II (1838) came to visit Bergamo.
In 1826 his health began to decline: in 1832 he showed the first symptoms of future blindness. In 1844 his wife died. The following year he passed away.
A cultivated musician, literatus, historian, Mayr was a fundamental personality for the cultural and social life of Bergamo. He had directed the Cappella in S. Maria Maggiore all his life long (since 1802) and the Lezioni Caritatevoli di Musica (since 1806), collaborated with the Teatro della Società opened in 1809, established the Pio Istituto Musicale a favore dei musicisti a riposo e delle loro vedove (1809), founded the Unione Filarmonica (1823), directed the Ateneo (1823-26).