The clavichord was a very simple instrument of keys and strings. The length of the vibrating string (which determines its pitch) was set, at the stroke which set it in vibration, by a metal ‘tangent’ on the end of the key lever, being at once the hammer and the fret of the string. The stroke was slight, the tone was extremely soft. The vibration continued only a few seconds and was so slight that anything like the ‘singing tone’ of the pianoforte was impossible. But within the duration of a single note the player, by a rapid upward and downward movement of the wrist which varied the pressure on the key, could produce a wavering tone similar to the vibrato of the human voice and the violin, which gave a faint but live warmth to the tone, unhappily wholly lacking in the tone of the pianoforte. It was doubtless this peculiar ‘live’ expressiveness which made the instrument a favorite of the great Bach, and which, moreover, justifies the player in making the utmost possible variety of tone in playing Bach’s clavier works on the modern instrument. The sound of the instrument was something like that of an æolian harp, and was therefore quite unsuited to the concert hall. But it was of a sympathetic quality that made it a favorite for small rooms, and much loved by composers for their private musings. The harpsichord was the concert piano, so to speak, of the time. Its strings were plucked by means of a short quill, and a damper automatically deadened the tone an instant afterwards. The instrument was therefore quite incapable of sustained melody, or of gradations of volume, except with the use of stops, which on the best instruments could bring new sets of strings into play. Its tone was sharp and mechanical, not very unlike that of a mandolin.