“He who makes songs without feeling
Spoils both his words and his music.”
Guillaume de Machaut (1300–1377) French poet and composer
Qui de sentement ne fait,
Son dit et son chant contrefait.
"Remede de Fortune", line 407; translation from Josiah Fisk and Jeff Nichols (eds.) Composers on Music (Boston, Northeastern University Press, 1997) p. 5.