It is difficult to condense Bach's very polyphonic orchestra on two staves without sacrificing clearness. At the sixth and seventh bars of our example, where the parts on the lower staff appear to cross, it must be remembered that the bass is still really the lowest part, because it is doubled in the lower octave by the double basses and the pedals of the organ. The figured bass is in Bach's own score, though we have in one or two details modernized his notation, as, for instance, where he writes ♭7 instead of ♮7, according to the custom of his day. The passages in which there is nothing but a figured bass were accompanied on the organ. The independent accompaniment of the orchestra, with the contrasted tones of the strings and oboes, is continued through the greater part of the fugue.
438. The following passages from Cherubini's first mass, which is for three voices only, show how thin harmony in the voice parts can be filled up.
