In this Mozart 2006 year, Henle Publishing launches the publication of the Urtext edition in three volumes (parts and study scores) of all Mozart string quintets. This publication begins with volume no. II, which includes the best known and most played quintets, in C major (K. 515), G minor (K. 516) and C minor (K. 406 / 516b) of the year 1787. This Urtext edition has a little sensation. It exploits for the first time a source hitherto unknown: there is little indeed, Ernst Herttrich, one of the two publishers, discovered handwritten parts relating to these works, material presenting additions by the hand of Mozart, in particular concerning dynamics and rhythmic accentuation.