ABSTRACT
This chapter argues that at least some surviving sets of manuscript parts can reasonably be interpreted as complete performance material; if this is true, then such parts can provide direct information about the size of the orchestras that used them. Personnel lists for eighteenth-century Viennese orchestras are abundant, but by and large these lists are limited to theater orchestras or to the orchestra of the Habsburg court. Eighteenth-century music theorists had comparatively little to say about orchestral size, and Viennese theorists said nothing at all about it. Eighteenth-century Viennese concerto parts often show little or no wear and some were probably never used. But the high-quality Italian paper commonly used by Viennese copyists shows little wear in any case, and wax drips, fingerprints, and corrections are sufficiently abundant to indicate that at least a substantial proportion of the sources were actually used.
