According to David Schulenberg, Renaissance composers did not, as a general rule, specify which instruments were to play which part; in any given piece, "each part playable on any instrument whose range encompassed that of the part." Nor were they necessarily concerned with individual instrumental sonorities or even aware of idiomatic instrumental capabilities. The concept of writing a quartet specifically for sackbuts or a sextet for racketts, for instance, was apparently a foreign one to Renaissance composers. Thus, one might deduce that little instrumental music "per se" was written in the Renaissance, with the chief repertoire of instruments consisting of borrowed vocal music.