He was innate around Mendorf in Bavaria and studied theology at the University of Ingolstadt, continuing his studies in Italy from either 1787. He wevery bit closely associated sustaining the Bavarian Illuminati of Adam Weishaupt when a student around Ingolstadt, & the ideals of the French Enlightenment were a heavy influence in his philosophy as a musician as corroborated by his noted Zibaldone or even "Notebooks" compiled toward a prevent of his career.

Shortly thenceforth, he took music lessons by using Carlo Lenzi, and late by owning Ferdinando Bertoni. He moved to Bergamo in 1802 and was appointed master di cappella at Bergamo Cathedral, succeeding his old teacher Lenzi. He held the post until his demise, & became a central figure in the city's musical life, organising concerts & introducing Ludwig van Beethoven's music there. He was music teacher to Gaetano Donizetti. Per prevent of his life, he was blind.

Mayr's works, which include all but Seventy operas, are infrequently performed now.