The composer's power has evidently grown as he worked, and the later quartets are by far the most original. The second movement of the fifth (159 K.), an allegro 3-4 in G minor, following an andante in B flat major, has, through its rhythm and modulation, an expression of dry humour that is quite suggestive of one of the later scherzos. Six quartets, composed in August and September of the same year, at Vienna, stand on a far higher level, and were probably written to order (168-175, K.). The superscription of the first shows that the whole six were planned together; they were written in quick succession, and their variety represented the different tendencies of the quartet style. In Vienna, of all places, the birthplace and domain of Haydn's chamber-music, the ambitious youth would exert himself to satisfy the demand for the highest class of compositions. Most of them have the approved four movements, and the composer's invention and execution keep pace with the more extended scope of the composition. The quartets are manlier and more mature than in the earlier works of the kind; but the singular beauty of form, the grace and freshness of Mozart in his full development, only show themselves in momentary gleams of inspiration. An effort to mould the raw material into form by means of skilful workmanship, and to make it subservient to the {INSTRUMENTAL MUSIC.} (312) spirit, is apparent throughout. We can see traces already of the study and preparatory work which resulted in the fine and serious compositions of the following year--the Masses in F and D major, and the Litany in D major. First and foremost is apparent the effort to analyse and vary the musical materials ready to hand by means of counterpoint. The first and last quartet end with a thoroughly worked-out fugue, complete with stretto and inversions. The close of the first fugue ended abruptly; Mozart has therefore erased the last four bars, and has substituted the subject in unison, thereby producing a lengthened and very effective conclusion. The second fugue is not by any means so fresh and lively as the earlier one, but it is richer in artistic work. Nor are Mozart's studies in counterpoint apparent here only. An adagio (168 JK.) begins with a four-part canon and retains the same character, although not so strictly carried out; in tone and substance this is one of the best of the series. Imitation is the rule in the elaboration of the first movements; and in the last quartet the whole of the first movement in D minor is built upon one characteristic motif. A free movement of the parts, a skilful employment of passages, variety of instrumentation, and other such means for giving life and animation to the music, are carefully provided, more especially in the minuets. An examination into details will discover traces of careful and delicate handling throughout the work.