Pseudo-Plutarch, De musica
Goodwin, Ed.

Manifest from hence therefore it is, why the ancient Greeks, with more reason than others, were so careful to teach their children music. For they deemed it requisite by the assistance of music to form and compose the minds of youth to what was decent, sober, and virtuous; believing the use of music beneficially efficacious to incite to all serious actions, especially to the adventuring upon warlike dangers. To which purpose they made use of pipes or flutes when they advanced in battle array against their enemies; like the Lacedaemonians, who upon the same occasion caused the Castorean melody to be played before their battalions. Others inflamed their courage with harps, playing the same sort of harmony when they went to look danger in the face, as the Cretans did for a long time. Others, even to our own times, continue to use the trumpet. The Argives made use of flutes at their wrestling matches called Stheneia; which sort of sport was first instituted in honor of Danaus, but afterwards consecrated to Jupiter Sthenius, or Jupiter the Mighty. And now at [p. 122] this day it is the custom to make use of flutes at the games called Pentathla, although there is now nothing exquisite or antique, nothing like what was customary among men of old time, like the song composed by Hierax for this very game; still, even though it is sorry stuff and nothing exquisite, it is accompanied by flute-music.