Institutio Oratoria
Quintilian
Quintilian. Institutio Oratoria, Volume 1-4. Butler, Harold Edgeworth, translator. Cambridge, Mass; London: Harvard University Press, William Heinemann Ltd., 1920-1922.
It is recorded that the greatest generals played on the lyre and the pipe, and that the armies of Sparta were fired to martial ardour by the strains of music. And what else is the function of the horns and trumpets attached to our legions? The louder the concert of their notes, the greater is the glorious supremacy of our arms over all the nations of the earth.