Mozart, "Dissonance Quartet", in C major

"... Mr. Joseph Haydn and the two Barons Tinti visited us on Saturday. We heard the new quartets, but only the three most recent ones, the ones he composed in addition to the other three we already have; they are indeed a little 'easier,' or 'lighter,' but splendidly composed. Mr. Haydn told me: 'I tell you before God, and give you my word of honor, that your son is the greatest composer I have ever known, personally, or in name. He has a taste and a great talent for composition...".

With these words, Leopold Mozart, visiting Vienna, related to his daughter Nannerl in February 1785 the impression that Wolfgang's last three quartets made on Haydn. Together with the three previous ones mentioned by Leopold, Mozart sent them to Haydn on September 1, 1785, offered to him in an affectionate letter in which he transferred to him "all my rights to them".

Known today as the "Haydn quartets", they were composed between 1782, the year of Mozart's arrival in Vienna, and 1785.
The Quartet in C major, popularly called "dissonance quartet", is the last of the series, completed on January 14 of the latter year and, according to Leopold, one of those heard at the evening in Haydn's presence.

Dissonance?
The moniker refers to the opening passages of the first movement and, as usual when it comes to nicknames, has nothing to do with Mozart. Nor does it have anything to do with a harmonic occurrence capable of shattering the listener's ears. The "dissonance" is heard in the first bars of the opening movement and consists of a chord progression over a "pedal note" carried by the cello. It may not have been a popular device at the time but it fully complies with the rules of eighteenth-century harmony.

Haydn's approach
But it is also said that it caused more than one tantrum in one or another distinguished aristocrat, which led him to tear the score into a thousand pieces. Also, some respectable performers returned the work to the publisher with corrections in their own handwriting. However, the very dedicatee of the six quartets, Joseph Haydn, discreetly pointed out that if that was how Mozart had written it, that was how it should be.

What Mozart sets out is simply to create a deliberate sense of ambiguity. He keeps us in the fog, in the dark, the misty, for the first few bars until the familiar C major chord appears, and the soul returns to our bodies.

Quartet No. 19 in C major, K 465, "Dissonance" - Movements
As usual for a string quartet, its movements are four, with two calm movements framed by two allegros.

00:00  Adagio - Allegro
10:00  Andante cantabile
17:30  Menuetto - Allegretto
22:44  Allegro molto