The greatest teachers of the past were singers and musicians who knew by hearing, not by observation alone, what beautiful tone and perfect expression were. That was the rock upon which they built their knowledge. The statement that they had no definite knowledge is in reality without foundation. And some of their knowledge was scientific. Science is knowledge gained by systematic observation, experiment and reasoning; also, knowledge coordinated and arranged. The former is true of the old school, and perhaps even the latter. Mancini certainly tells us some very definite things about his own observation and teaching; so does Tosi, so do others. Mancini particularly tells us that the fauces must point forward, and calls attention to the fact that “modern singers” (that is, singers of the latter half of the eighteenth century) were trying to get more power by stretching or tensing the fauces, to the detriment of their voices, which one assertion tells us as plainly as possible that he believed in singing with freely active fauces, which means freely active palate, at least without willful tension applied locally.
Witherspoon, Herbert. “Singing.” New York: G Schirmer (1925).