[80] This movement is in three parts, and the allusion is to the two upper voices, which maintain a duet in cantabile on a gently moving quaver bass.
[81] The idea of the two subjects, and of the “free” section after the central double bar, was already realised incompletely. In the shortest “binary” movements the scheme of keys is found to be P, Q. (double bar) || Q, various, P.
[82] This paragraph is suggested by a corresponding one in the author’s German edition.
[83] The author means such composers as Rameau, Galuppi, Couperin, who wrote for their audience to a great extent.
[84] This expression may be misunderstood unless reference is made to the music. The passage arrives at the key of B (the “dominant” key), but the F sharp mentioned is merely the bass note.
[86] A “ground” bass is a short passage repeated an indefinite number of times through an extensive movement. In this case it consists of four bars, and is not repeated so strictly as usual, though its general figure is kept up throughout.
[87] This expression, “deceptive” cadence, is a translation of cadenza d’inganno, one of the several cadences or closes which had names given to them by the old theorists. The “inganno” cadence was something like the “interrupted” cadence, but was supposed to lead into another key, hence the “deception.”
[88] The author possibly refers to the flowing freedom of the counterpoint in the quintet in Wagner’s opera. But there is no need nowadays to demonstrate that the Bayreuth master is as necessarily a contrapuntist as he of Weimar.
[89] Meaning, of course, that the fingering methods of the father and son are by no means identical. The former employed the crossing of the fingers over one another freely; whereas Philip Emanuel’s notions of fingering are practically ours. See his “Exempel nebst achtzehn Probe-Stücken, etc.,” date 1780.