 Some time afterwards, he wrote his String Quartet in G major, K. 387, with a finale that is also a fugato and also begins with a theme consisting of four whole notes first stated by the second violin.Having the first 45 measures in Mozart's hand, it was natural for Köchel to assume that Mozart was the author.This symphony is one of the few by Michael Haydn to have a slow movement in a minor key (the others are No.s 6, 9 and 20) though in this one the D minor key signature changes to D major around the middle for the rest of the movement.