A type of music that angsty teens listen to while they pretend to cut themselves.
Not hard enough to be called Punk but not bubble gum enough to be called pop. Imagine if Punk, Pop, and a little bit Goth got together and had a child. Emo is what you would get every time because it takes a little bit of everything.
Just take one band and switch the names around and you basically have every emo band imaginable. The same whiny sounding lead singer, the same sounding guitar solos, the same lyrics just in a different order.
Those people who say that My Chemical Romance is emo don't know the physiological level there music is really on. Wow, those guys are so deep and bruting.