Salieri and Gassmann arrived in Vienna on 15 June 1766. Gassmann's first act was to take Salieri to the Italian Church to consecrate his teaching and service to God, an event that left a deep impression on Salieri for the rest of his life. Salieri's education included instruction in Latin and Italian poetry by Fr. Don Pietro Tommasi, instruction in the German language, and European literature. His music studies revolved around vocal composition and thoroughbass. His musical theory training in harmony and counterpoint was rooted in Johann Fux's "Gradus ad Parnassum", which Salieri translated during each Latin lesson. As a result, Salieri continued to live with Gassmann even after Gassmann's marriage, an arrangement that lasted until the year of Gassmann's death and Salieri's own marriage in 1774. Few of Salieri's compositions have survived from this early period. In his old age Salieri hinted that these works were either purposely destroyed or had been lost, with the exception of a few works for the church. Among these sacred works there survives a Mass in C major written without a "Gloria" and in the antique a cappella style (presumably for one of the church's penitential seasons) and dated 2 August 1767. A complete opera composed in 1769 (presumably as a culminating study) "La vestale" ("The Vestal Virgin") has also been lost.