Isn't the Mudcat great ? Where else could we learn that 4ths in the middle ages were known as "strong, weak, electromagnetic, and gravitational" ?

M.Ted, I think you're right about treatises in the sense that the vertical augmented 4th and diminished 5th would have been classified as dissonances, not as consonances.

But when folks repeat the tale that the tritone was "banned" or "outlawed", or associated with devils, I think they are stating something more than that the tritone was considered dissonant. As I interpret, they seem to mean that someone would have been dismissed from his post, or jailed, or excommunicated, for using a horizontal or vertical tritone at all, not that he would have been considered an inept musician for using a dissonance at a point in the music when he should have used a consonance.

T[àskëmus]