''''Symphony No. 9 in C major''', K. 73/75a, by Wolfgang Amadeus Mozart, was likely composed in July 1772Volker Scherliess: Die Sinfonien. In: Silke Leopold (Hrsg.): Mozart-Handbuch. Bärenreiter-Verlag, Kassel 2005, ISBN 3-7618-2021-6, pp. 277-278 in Salzburg between his second and third Italian journeys.
The symphony is in four movements and is Mozart's first extant symphony in the key of C major. There is no information concerning which of the many Italian concerts given by the Mozarts during this visit saw this symphony's first performance. The autograph score is preserved in the Biblioteka Jagiello\u0144ska in Kraków. ISMN M-006-20466-3