In basic music theory, you learn that the interval known as a tritone, or three whole steps from one note to the next, was once called "the devil's interval." Three whole steps would be going from B to F, or E to Bb, or D to Ab. D-E-F#-G#(or Ab)In medieval times, this interval was considered so dissonant, that it was avoided. These days, it's everywhere because that whole devil stuff is stupid. During tonight's in-class discussion, one of the more annoying vocalists said "you would never teach the devil's interval to kids because it's hard to sing." Now, it is hard to sing for untrained ears, but "devil's interval?" Really? This is why I hate people. And this is why there's such a huge dichotomy between instrumental & vocal music in schools. Vocalists are looney tunes.