will suffice to show the vast difference between the treatment of the pianoforte by Mozart and by Clementi. Clementi presents passages in thirds and sixths, he uses octaves in rapid succession, he widens the chords, and exhibits for the first time a hitherto unknown muscular force. The compass of the piano of Haydn and Mozart's Sonatas—5 octaves (rarely 5½ and less rarely 6) was soon extended to 6 and 6½ octaves, and the instrument became for the first time a powerful, rich, sonorous, and highly effective one. The fact that Clementi entered into partnership with the firm of Collard, testifies to his keen and lively interest in the pianoforte manufacture, and is a guarantee for his intimate acquaintance with the connexion between the mechanism of the instrument and the minutest details of pianoplaying. Compared with the manner in which Clementi writes his most difficult Sonatas and Studies—Concertos by him do not exist—the style of Haydn and Mozart appears almost small, thin and poor. Whilst Haydn and Mozart regard the instrument merely as a vehicle to convey their ideas, and think more of musical substance than of technical brilliancy, Clementi uses the instrument and the musical art rather for the display of his remarkable manual dexterity: his compositions are clever, in some instances grand and even bold, but on the other hand, they lack grace and especially warm and enthusiastic feeling; in short they do not possess that feu sacré which distinguishes so many of the productions of Haydn and Mozart, and which place Beethoven's works on so very high a pinnacle. Mozart's contemporaries declare Clementi to have been superior to Mozart in technical execution, brilliancy of effect, and masculine force of expression; they almost unanimously praise Clementi's thoroughly-trained velocity, the quiet position of his hands, the extraordinary power and fulness of his touch, the clearness and equality of his performance, and the judicious delivery of his slow movements. Clementi wrote for the pianoforte only, for the few Symphonies which he composed in 1820, when already 68 years old, count for little; the piano was therefore his only medium of expression, and the one chosen exponent of his activity as a composer. It was everything to him, and to the keyboard he entrusted every idea that crossed his mind. His ideas consequently adapted themselves by degrees to the nature of the instrument, and thus his Sonatas may with truth be called types of pianoforte compositions; for these he invented effects, technical passages, figures, combinations; and like Columbus, discovered a new world on the pianoforte. And this peculiar position of Clementi in relation to the piano explains the fact that Beethoven preferred his Sonatas to those of Mozart.
The extraordinary effect produced by Clementi brought him a host of admirers and followers, and he soon became one of the most desired of teachers. The difference between his style and that of Mozart resulted in the distinction between the so-called 'Vienna' or 'Mozart' school, and the 'Clementi' school. The original cause of this difference is chiefly to be sought in the instrument itself. Clementi used the English, Mozart and his successors the Vienna pianoforte. The English instrument had a richer, fuller and more sonorous tone, the hammer had a deeper fall, and was thus favourable to the sure execution of thirds, sixths, and octaves, and to the clear and precise playing of chords in succession; the tone of the Vienna piano, though thin and of shorter duration, was highly agreeable, and its action was so light that (as in the harpsichord) the most delicate pressure produced a sound from the key. From this facile mechanism results the rather extraordinary expression 'to breathe upon the keys,' an expression which the most distinguished disciples of the Vienna school, Hummel and Czerny, frequently used, dementi's piano was therefore favourable to a substantial and masculine treatment; while the Vienna piano responded best to a rapid fluent style and to arpeggio playing. Clementi's piano was furthermore well adapted to the cantabile, and some of his pupils (as J. B. Cramer and John Field) made good use of this advantage, while the Vienna players, feeling the weak points of their native piano, sought by cleverness and taste to make up for its deficiencies, and surrounded their cantabile with such quantities of light, airy, elegant, tasteful passages, runs, broken chords, and ornaments of all kinds, as in great measure to hide the failing. The Vienna school strove rather to retain the character of the piano as a chamber instrument, whilst the stronger and more solid construction of the English one tended to make it an exponent of orchestral music. Both schools have their distinct history. The Vienna one deteriorated sooner than that of Clementi; after Mozart's death it lost much of the intellectual force and the innate gracefulness and affectionate warmth that distinguish the best of his Sonatas and Concertos, and some of his smaller pieces. With Hummel and Moscheles it reached its climax. Hummel's playing was distinguished by certainty, correctness, and transparent clearness, an admirable evenness and subtlety of touch, and refined and correct rhythmical feeling. His high and exceptional powers as a performer were, however, best shown in his extempore playing, a department in which he had no rival. Moscheles, superior to Hummel in the variety of his tone-gradations (light and shade of touch), and in a more decided and energetic bravura style, excels him also in grace and elegance; but both were wanting in warmth and spontaneity. In Mozart technical execution and intellectuality were still evenly balanced; with his successors—although both Hummel and Moscheles wrote works deserving the epithet 'classical'—technical execution gains the preponderance, and this led Woelfl (1772–1812), Steibelt (1764–1823), Czerny (1791–1857), and Herz (1805– [App. p.748 "1806"]) to devote themselves entirely to the demand for public amusement and momentary excitement, and thus to lose sight of the principles which made the school of Mozart so great.
