Keltani
I just think it is funny that the only interval that sounds different, possibly unstable, and is widely discouraged, is the tri-tone. When you are just playing intervals to see what sounds good or something the one that most people don't think about using in power chord standards is the tri-tone until they hear that it raises the devil or that is sounds okay with distortion.
Oh, I LOVE the tri-tone! Especially the #4 in Lydian. I also use them ALL the time by themselves... with and without distortion.
There's also the m2 that people don't like. I can't remember which one it is... but the m2 or the tri-tone is the most physically dissonant interval.
