In most cases analyzed, microstructural changes experienced, during preludial compression, by the PPTA fiber containing side-group defects were permanent.
In sharp contrast to the finding just described, in the case of PPTA fibers containing side-group defects, preludial axial compression is found to change the longitudinal-tensile strength.
They have an air of preludial
improvisation and were to remain a common feature of keyboard concerto language, as found, for instance, in the development sections of the Mozart concertos.
In addition to a section on Gregorian chant in Chapter 1, for instance, we find brief discussions of madrigal, monody and recitative, of cadences and cadenzas, and of preludial
forms - all seen as reflections of the urge towards intense expression and improvisatory freedom.
Such a proportional weighting of the Prelude and opening scene finds a certain justification, perhaps, in the context of this "preludial
" drama, itself so much preoccupied with origins and first causes.
John Daverio argues not only that dance suites were much more common in Austro-German and English sources than in those from Italy but also that Georg Muffat may have served as a primary conduit through which Corelli caught on to the idea of grouping particular dances to form a chamber sonata.(9) The statistics Daverio presents are impressive: in Italian publications he found only 30 examples of rudimentary suites (i.e., preludial
movements followed by dances clearly specified as belonging together), but ten times that number (300) in 27 contemporary Austrian and German sources (1650-1700).