QUOTE: The term emo originated in the 1980s to describe a genre of music stemming from the hardcore punk music scene in Washington, D.C. Early bands labeled emo (or sometimes emocore) in this scene included Rites of Spring, Embrace, and Fugazi. The term emo as a music genre has become broader and broader with time, and now is loosely understood to mean "rock music with emotionally-based lyrics or effect."
https://en.wikipedia.org/wiki/Emo_%28slang%29