It is at this point that the great need is felt. A mechanical advance is required to bring the expressive capacity of the clavier into a line with the demands of genius upon it. The rivalry between the clavicymbal and the clavichord[92] was not yet quite decided. In Romance lands the former was the favourite; in Germany the latter. On the former great effects could be better produced; on the latter the more soulful tone, and the unique embellishment called “Bebung.” Bach wrote much, including the Wohltemperiertes Klavier, for the clavichord, which even his son Philip Emanuel still preferred to the clavicymbal. But he was so unable to disguise from himself the counter advantages of the fuller and broader quill-instrument, that he published pieces for “Kiel-flügel”[93], with two manuals and registers for forte and piano. These registers were the only means for giving light and shade to the monotonous note of the “cymbal”; to give light and shade by turns, as in the organ, so that on the upper manual a melody could be played loud, and on the lower the accompaniment could be played soft. In Kuhnau we see the forte and piano, which he aimed at by simply striking on the clavichord, used as a means of expression. In the Biblical Stories Jacob has just been cheated by Laban, in receiving Leah for Rachel. “The bridegroom is contented,” as a minuet shows us; but “his heart prophesies misfortune,” and the measure rushes on, becomes piano and più-piano; suddenly Jacob takes heart again--forte; after a bar or two he goes to sleep--piano; he wakes--forte; falls into deep slumber--piano. In his “Italian Concerto” Bach had made a much more specialised use of this by the register. He had mingled loud and soft parts, and each hand alternately is marked forte or piano. In these, and similarly in the echo-movement of the suite with “Ouverture à la manière française,” we are led to think of a splendid clavicymbal, such as the one preserved ostensibly as Bach’s in the Berlin Museum of Instruments. In that, every one of the combinations of four strings can be altered by pulling a register: the manuals admit of coupling, and a soft lute-stop is provided. [Illustration: Pedal-clavichord. Consisting of two manual clavichords, with two strings to each note, of (8 ft. and) 4 ft. tone, and a pedal-clavichord with four strings to each note, two 16 ft. and two 8 ft. Inscribed “Johann David Herstenberg, Organ-builder at Geringswald, made us, 1760.” De Wit collection. ]