The transitional passage which was then to accomplish the modulation to the dominant or relative major key in which the second theme was to be announced, tended to become highly conventional, a sort of service music with little more than formal significance. Usually a figure of some technical brilliance carried the music along in repetitions that could not fail to attract the attention of the listener and arouse his curiosity as to what was coming next. These figures might or might not be fragments of the opening theme. The modulation to the desired key having been accomplished, the passage came to an end in a flourish or in a pause of a beat or two. No feature of the triplex form is more distinctive than these conventional transitional passages which seem to carry on the double function of porter and herald. After the claim to attention had been thereby established the second theme was allowed to sing. The general tendency was to give to this second theme a gentler and more truly melodious character than the first. Here was the great domain of the Alberti bass, for instance. And following the second theme came another busy little passage, service music again, of which the duty was to bring the first section of the movement to an orderly close in the key of the dominant. The treatment of the middle section varied. It remained always the part in which the composer exercised the most freedom. It might be long or short, in the manner of a fantasia; it might merely present fragments of the first or second themes or both in a series of modulations or sequences. It may be said that the tendency towards a more or less dramatic development made an appearance before the end of the century, as if the composer was submitting his will to the suggestions of the themes themselves. The greater the inherent vitality of these themes the more likely were they to assert themselves in this middle section and to reveal, as it were, the germinating power within them and color the section with their nature. The end of the section was more and more contrived to lead up to the last section in an obvious manner, either with a long run, a series of flourishes reaching a climax, or a pause, or anticipations of the coming theme. The last section differed little from the first except that the second theme now appeared in the tonic key. The transitional passage was taken, along with the themes themselves, from the first section; but, relieved of one half its duty--that of bringing to pass a modulation from tonic to dominant--was likely to be considerably shortened. The closing measures, however, were usually an exact reduplication in the tonic key of those which had closed the first section in the dominant. The first section was always repeated, and so were the second and third, _en bloc_.