Pseudo-Plutarch, De musica
Goodwin, Ed.

We are next to consider whether the masters of music are sufficiently capable of being judges of it. Now I aver the negative. For it is impossible to be a perfect musician and a good judge of music by the knowledge of those things that seem to be but parts of the whole body, as by excellency of hand upon the instrument, or singing readily at first sight, or exquisiteness of the ear, so far as this extends to the understanding of harmony and time. Neither does the knowledge of time and harmony, pulsation or elocution, or whatever else falls under the same consideration, perfect their judgment. Now for the reasons why a musician cannot gain a perfect judgment from any of these, we must endeavor to make them clear. First then it must be granted that, of things about which judgment is to be made, some are perfect and others imperfect. Those [p. 130] things which are perfect are the compositions in general, whether sung or played, and the expression of those, whether upon the instruments or by the voice, with the rest of the same nature. The imperfect are the things to these appertaining, and for whose sake they are made use of. Such are the parts of expression. A second reason may be found in poetry, with which the case is the same. For a man that hears a consort of voices or instruments can judge whether they sing or play in tune, and whether the language be plain or not. But every one of these are only parts of instrumental and vocal expression; not the end itself, but for the sake of the end. For by these and things of the same nature shall the elegancy of elocution be judged, whether it be proper to the poem which the performer undertakes to sing. The same is to be said of the several passions expressed in the poetry.