Together with Georg Christoph Wagenseil and Josef Starzer, Monn formed the Viennese Pre-Classical movement ("Wiener Vorklassik"), whose composers are nowadays mostly known only by their names.
However, his successful introduction of the secondary theme in the symphony was an important element for the First Viennese School (Haydn, Mozart, Beethoven and Schubert) that would come some fifty years later.
Together with Georg Christoph Wagenseil and other contemporaries such as Leopold Mozart and Josef Starzer, Monn could be said to represent a school of Austrian composers who had thoroughly studied the principles of counterpoint as practised by Johann Sebastian Bach and Johann Joseph Fux, but also effected a change from the formalistic, imposing and ornate Baroque style to the simpler, more graceful Galante music.
The catalog of works written by Matthias Monn contains sixteen symphonies, a score of quartets, sonatas, masses and compositions for violin and keyboard.
Schoenberg also wrote "continuo realizations" for several works by Monn, including a cello concerto in G minor which was recorded by Jacqueline du Pré.