There has never been so much confusion around a genre as there is with emo.
Let's start by saying that there are two completely different types of emo.
The first and original "emo" is a kind of hardcore that's even more "intense," about which I know very little, so I wonāt comment further, emerging in the early 90s if Iām not mistaken. One original emo band is Circle Takes The Square, the only one I've listened to a bit.
The term "emo" resurfaces throughout the 90s with bands like The Get Up Kids, Sunny Day Real Estate, The Juliana Theory, and Further Seems Forever. This type of "emo" can be defined as very melodic rock... up to this point, however, there's still no sign of emo boys and emo girls.
Later on, Taking Back Sunday pops up, and with their "Tell All Your Friends," they inherit the legacy of the aforementioned bands, and perhaps their first album deserves to be called "emo."
Chaos ensues when the so-called āemocoreā emerges, with bands like UnderOath and A Static Lullaby, which offer a kind of post-hardcore characterized by alternating melodic and screamed vocals, powerful riffs, and catchy choruses.
Over the years, emocore becomes increasingly "trendy," and a myriad of bands start popping up, all offering the same formula.
The chaos escalates when:
1) For silly kids, thereās no longer any difference between emo and emocore: whatās emo is emocore and vice versa.
2) Since it sounds very "cool" as a word, any type of album is labeled "emocore" or "emo."
Nowadays, bands that play completely different genres, from pop/punk to powerpop to rock/pop to metalcore to post-hardcore, are considered "emo."