profoundly moving though they are, are quartet movements, only requiring
a larger number of instruments because greater fullness and force were
needed to make the music satisfying in a large hall. Mozart's music was
entirely different in texture. One cannot imagine the slow movement of
the G Minor Symphony without wood wind. Haydn knew what his music was,
and what orchestration it wanted, and he never dreamed of
over-orchestrating. What he would have said of such music as that of
Berlioz, where the orchestration is ridiculously out of proportion to
the phrases, where the orchestra makes all the effect, if any at all is
made, I cannot guess. He used extra instruments when he needed them, as,
for example, in the "Military" symphony. The touch of instrumentation in
the andante of the "Surprise" is another instance. The idea of scaring
sleepy old ladies with a sudden bang on the drums--the kettle-drum
bolt--is often mentioned as an example of Haydn's "humour."

When we compare the London symphonies to the earlier ones, we feel at
once a stronger, more vehement spirit driving the music on. They seem
richer in themes than the others, partly because the themes are bigger,
partly because they are more perfectly adapted to monodic, harmonic
treatment, and out of every bar something is made. A theme is pregnant,
of course, according to what a composer sees in it and gets out of it.
Who would know this of old Clementi--

[Illustration: some bars of music]

--if Mozart had not woven the _Zauberflöte_ overture out of it? And who
save Beethoven saw the possibilities of this?--

[Illustration: some bars of music]