writing music, endless in its variety of outline and colour and changing
sentiment, on a ground-bass--_i.e._, a bass passage repeated over and
over again until the piece is finished. The instrumentation must have
been largely dictated by the instruments placed at his disposal, though
we must remember that in days when it was an everyday occurrence for,
say, an oboist to play from the violin part save in certain passages,
even an apparently complete score is no secure guide as to what the
composer meant, and as to how the piece was given under his direction.
This remark applies to the scoring of much of the theatre music. The
_Theatre Ayres_ contain only string parts, and it is nonsense to suppose
that in the theatre of that time Purcell had only strings to write for.
Purcell wrote in all twenty-two sonatas--twelve in three parts, ten in
four. So far as the number of parts is concerned, there is little real
difference. In the three-part works one stave serves for both the string
bass-player and the harpsichordist; in the four-part ones there are two
separate staves, with trifling variations in the two parts. The twelve
three-part sonatas were issued, as has been said, in 1683. They are
pure, self-sustaining music, detached from words and scenic
arrangements; nothing approaching them had been written by an
Englishman, nor anything so fine by an Italian. Indeed, in their own
particular way they are matched only by the composer's own four-part
sonatas published after his death. We must not look for anything like
form in the sense that word conveys nowadays; there is no unalterable
scheme of movements such as there is in the Haydn symphony, and within
each movement there is no first subject, second subject, development and
recapitulation. All that had to be worked out nearly a century later.
The set forms of Purcell's day were the dances. The principle of
Purcell's sonata form is alternate fast and slow movements. Nothing more
can be perceived; there is nothing more to perceive. Sometimes he
commences with a quick piece; then we have an adagio or some slow dance;