Emo is a fashion and music style that originated in the 1980's. Emo music consists of screaming, and ncredibly poetic lyrics. It is short for Emotional Hardcore, as it began as a form of punk rock. Emo bands include (but are not exclusive too): My Chemical Romance, Aiden, Taking Back Sunday, The Used, Fall Out Boy, Jimmy Eat World, Panic! At The Disco, Scary Kids Scaring Kids, Hawthorne Heights, Linkin Park, Three Days Grace, Escape The Fate, Die Mannequin, AFI, The Academy Is.., Cute Is What We Aim For, Dashboard Confessional, From First To Lst, Funeral For A Friend, Rites Of Spring, Silverstien, Thrice, Thursday, Coheed And Cambria, and Underoath. Some emo, such as PATD, has been known to have a dance/techno aspect to it.
Emo fashion is far more easier to define. When it comes to hair, black is usually the staple, although any colour is acceptable (my natural hair colour is actually barbie doll blonde). Hair normally covers half the face, and is straight. Spikes in the back is also emo. Clothes are mostly black, with the odd flouresant colour (such as pink) mixed in. Emo's wear ties, and scarves in just about any colour. An emo shirt is most likely a tight fitting black t with an emo band name on it, or anything from Nightmare Before Christmas or Emily The Strange.
Pants are ALWAYS tight-fitting skinny jeans. No exception. A girl can wear a black skirt overtop, or tight-black leggings (black with skulls is better) and the skirt. Denim in this situation is also acceptable.
Shoes can be converse, or vans. Writing on them (and your jeans) adds a nice touch.
Gloves are a staple of emo, if you can get them fingerless, even better.
Emo can also take on a gothic-hybrid style. Dress shirts and lace can be your best friend. ^^
Make sure you wear thick black eyeliner, black, purple, or grey eyeshadow, and black nailpolsh. Even if your a guy. Trust me, it's hot.
Also, I will say this once, and once only. Emo does NOT mean gay, depressed, or cutting. Emo kids are just being themselves.
Poser Emo: Dude, do you see these cuts? I'm so hardcore!
Real Emo: No, you're not. Get a life, poser.