The part of mystery surrounding its composition and its sponsor as well as the original date of the score, the incredible training required for its implementation, the never-surpassed quality of its writing for 12 voices (we will have to wait for Stravinsky in 1952 & his Concertino to 12 for a composer to dare to approach such broad training and writing), are all marks which make Mozart's Serenade K361 a true “musical Mona Lisa”. 

If the piece is well known to knowledgeable music lovers, everyone has already heard it without necessarily knowing it; indeed Milos Forman in Amadeus (the film with 8 Oscars and 53 awards) gives it pride of place: it is this piece (a tasty montage of the 3rd and 7th movements) which is played in the salons of the Prince-Archbishop of Salzburg then that Wolfgang and Constance banter under the reception tables and that later Salieri realizes…