I Second That Emotion

Musical affects: they used to be kind of a big deal.
Enter equal temperament and all of a sudden they didn't mean so much anymore - but no student is going to get through a music history class without some mention of "emotions associated with individual keys."
On the other hand, very few music students are going to take the time mid-semester to look up which emotion goes with which key (cough cough: I'm guilty) - and that's too bad, because there were some IMAGINATIVE music scholars when it mattered.

According to Schubart: Ab major is all about putrefaction, Db major is a leering key, and f# minor "tugs at passion like a dog biting a dress." And of course our theorists had their differences: Schubart was convinced Eb major was the only key for representing intimacy with God, while Charpentier labeled it "cruel and hard." Oops?

[French] Compare treatises by: Charpentier (1682), Mattheson (1713), Rameau (1722), Schubart (1806)
[Not-so-good English translation]

[English] Schubart's Ideen zu einer Aesthetik der Tonkunst ca. 1806

An excellent overview of "Characteristics of Musical Keys"