[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. [90] This method is still commonly practised. Chopin, Liszt, and others, supply innumerable examples, particularly of the passing of 4 over 5. [91] That is, “for the lute _or_ clavier.” [92] It is necessary once more to remind the reader of the _essential_ difference in “action,” power of expression, and strength of tone, between these two instruments; and of the unfortunate ambiguity which exists in the use of the name “clavichord.” _Vide supra_, pp. 21 and 89, note. [93] Kiel = quill, flügel = wing, _i.e._ a keyed instrument with a plucking “action” of _quill_ plectrums, with a case made in the shape of a bird’s _wing_. Grand pianofortes are still made in this shape, and therefore are still called “flügel” in Germany. Kiel-flügel is synonymous with clavicymbal (hence “cembalo”), and means “harpsichord.” [94] Agricola was a pupil of John Sebastian Bach, and in 1754 helped Bach’s son Emanuel to write a biography of his father. [95] Suggested by corresponding paragraphs. [Illustration: Philip Emanuel Bach, as he was in his Hamburg period.] The “Galant” School