What is this? This combines the preceding two charts. It shows a direct correlation between the degree of tempo volatility at the 'thematic' level and that at the 'sectional' level.

In plainer English: variety in the large is proportional to variety in the small. This is true of performances both very fast (Scherchen, Coates, Beermann, Norrington, Gielen) and very slow (Klemperer, Horenstein, Giulini, de Sabata, Asahina).

Exceptions. As usual, a very few conductors account for most of the exceptions, in this case Furtwängler and Knappertsbusch. Those in red are either relatively bland in the exposition (Masur) or eccentric in the development (Brüggen). Furtwängler pulls the tempo so far down at m.338 that it skews all his results.

Those in blue feature an Exposition significantly more eventful that what follows (Knappertsbusch, Pfitzner, Weingartner, Fried, Frederik IX). It may be significant that this includes three of very earliest recordings.

But the overall trend seems clear. It would be interesting to see whether this correlation holds at smaller scales.