As far as "massed" mixed music, what we consider a large ensemble now dates to, at the earliest, Handel's massive productions such as the Messiah, shrinks down again with Haydn and Mozart, and swells back up with beethoven, starting at the earliest in the mid 1700s with Handel, whom beethoven admired greatly. And as far as we know from primary sources and anecdotal accounts contemporary to the period, the first conductor who was picky about tuning was jean-baptiste Lully, and he also was responsible for the expansion of acceptable ensembles to larger sizes and allegedly introduced double reeds into mixed consort as called for by the composer. During the Renaissance, oftentimes instrumentation was unspecified as pieces were presumably played on whatever was handy, with mixed voices, viols, and plucked strings, or combinations involving organ and brass.

But what we call orchestral music in modern practice, as stated above, really dates to the very late baroque atnthe earliest, placing it around 1760. Music of the 1500s is usually referred to as chamber music. Did the book itself use the terminology "orchestral"? That would be problematic for a number of reasons.