tutti passages are longer and more important, which entails more participation by the orchestra in the solo portions. This gives a symphony-like character to the whole, to which the solo instruments add a peculiar brilliancy. In relation to each other they are simply treated. They generally relieve each other, either repeating whole phrases or sharing them between them; when together, they are mostly in thirds and sixths, and there seldom occurs a true two-part passage in which the two instruments move freely and independently. In this respect the concertone composed in 1773 (190 K.) is more artistic in design and in workmanship. Here the orchestra is in contrast with two solo violins, to which the oboe is added as a solo instrument; the violoncello, though not so freely treated as the others, is also often solo. The usual concerto form is given to the three movements, the middle movement being romance-like, but more elaborate than usual, to give employment to the solo instruments. The violoncello, though it does not take a leading part in this movement, has an independent passage as accompaniment throughout. The last movement is "tempo di menuetto," resembling those in the violin Concerto in A major (219 K.), the bassoon concerto (191 K.), the clavier concerto in C (246 K.), the triple concerto (242 K.), and the clavier trio in B flat (254 K.); the form of the minuet with several trios is treated with some freedom, and approaches that of the rondo. The forcible and independent treatment of the orchestra, both in the tutti and the solo passages, gives to the whole of this composition the character of a symphony; but the solo parts are grouped with greater variety, since there are four of them, and they do not as a rule repeat the same passages or join in unison. Sometimes the violins alternate with each other, sometimes the oboe joins them or opposes them, sometimes the oboe and violoncello are both in opposition to the violins, and sometimes all the four instruments move independently side by side. A strict and ingenious fugal structure was required to give unity to this manifold variety. In the first allegro especially the motifs are chiefly imitatively treated, and {MOZART'S TREATMENT OF THE VIOLIN.} (321) sometimes the varied rendering of a phrase necessitates a change of instruments; the coming and going of the instruments and their combinations are carefully planned, as well as the part taken by the orchestra in producing the general effect. In the two last movements alternation is the predominant principle, and the parts are only ingeniously interlaced here and there. The work displays throughout more of skilful mechanism and clever elaboration than of original invention and beauty.