Mozart String Quartet #19 (Dissonance) In 1785, Mozart published a set of string quartets that he dedicated to Haydn. So we’ll start there - with Haydn - for just a minute. Then we’ll get back to Mozart.   Joseph Haydn revolutionized string quartet writing. We could say he invented it, except he didn’t in all the ways - string quartets (meaning music written for 4 stringed instruments - usually, but not always, 2 violins, viola and cello) existed before Haydn, but he changed