Anton Cajetan Adlgasser
Born: 1st October 1729, Inzell, Germany
Died: 23rd December 1777, Salzburg, Austria
Nationality: German
Anton Cajetan Adlgasser was a German organist and composer at Salzburg Cathedral and at court, and composed a good deal of liturgical music (including eight masses and two requiems) as well as oratorios and orchestral and keyboard works.
Born in Inzell, Bavaria, he moved to Salzburg, where he studied under Johann Ernst Eberlin. From 1750 he was organist at the Salzburg Cathedral, where he remained the rest of his life. After a visit to Italy in 1764–5 he set Metastasio's La Nitteti (his only opera) performed in Salzburg (1767), and in 1767 he collaborated with Mozart and Michael Haydn on the oratorio Die Schuldigkeit des ersten Gebots. Mozart, who had a high regard for Adlgasser's music, succeeded him as Organist at Salzburg Cathedral in 1777.
Read more at https://en.wikipedia.org/wiki/Anton_Cajetan_Adlgasser