I do not understand what "emo" is. All right, I do understand that it stands for "emotional", of course, but I still understand what it really is. I've heard some bands, like The Juliana Theory or Stavesacre (bands that have topics about spiritual stuff, God, etc.) are considered emo. On the other hand, I've read an article describing emo as plenty of alternative rock bands such as Jimmy Eat World or American Football, which discuss the topics that too many modern songs talk about. (a significant other, angst at the world, angst at a signifcant other, etc.)

So, basically, I'm completely confused. What is "emo"?

I don't know.. I doubt that anyone knows, except Allmusic.com, of course.. so, this is what they have to say about it:

Originally an arty outgrowth of hardcore punk, emo became an important force in underground rock by the late '90s, appealing to modern-day punks and indie-rockers alike. Some emo leans toward the progressive side, full of complex guitar work, unorthodox song structures, arty noise, and extreme dynamic shifts; some emo is much closer to punk-pop, though it's a bit more intricate. Emo lyrics are deeply personal, usually either free-associative poetry or intimate confessionals. Though it's far less macho, emo is a direct descendant of hardcore's preoccupations with authenticity and anti-commercialism; it grew out of the conviction that commercially oriented music was too artificial and calculated to express any genuine emotion. Because the emo ideal is authentic, deeply felt emotion that defies rational analysis, the style can be prone to excess in its quest for ever-bigger peaks and releases. But at its best, emo has a sweeping power that manages to be visceral, challenging, and intimate all at once. The groundwork for emo was laid by Hüsker Dü's 1984 landmark Zen Arcade, which made it possible for hardcore bands to tackle more personal subject matter and write more tuneful and technically demanding songs. Emo emerged in Washington, D.C. not long after, amidst the remnants of the hardcore scene that had produced Minor Threat and Bad Brains. The term "emo" (sometimes lengthened to "emocore") was initially used to describe hardcore bands who favored expressive vocals over the typical barking rants; the first true emo band was Rites of Spring, followed by ex-Minor Threat singer Ian MacKaye's short-lived Embrace. MacKaye's Dischord label became the center for D.C.'s growing emo scene, releasing work by Rites of Spring, Dag Nasty, Nation of Ulysses, and MacKaye's collaboration with members of Rites of Spring, Fugazi. Fugazi became the definitive early emo band, crossing over to alternative rock listeners and getting press for their uncompromisingly anti-commercial attitudes. Aside from the Dischord stable, most early emo was deeply underground, recorded by extremely short-lived bands and released on vinyl in small quantities by small labels; some vocalists literally wept onstage during song climaxes, earning derision from hardcore purists. Fugazi notwithstanding, emo didn't really break out of obscurity until the mid-'90s emergence of Sunny Day Real Estate, whose early work defined the style in the minds of many. Tempering Fugazi's gnarled guitar webs with Seattle grunge, straight-up prog-rock, and crooned vocals, SDRE launched a thousand imitators who connected with their dramatic melodies and introspective mysticism. Some of this new generation connected equally with the wry, geeky introspection and catchy punk-pop of Weezer's Pinkerton album. While several artists continued to build on Fugazi's innovations (including Quicksand and Drive Like Jehu), most '90s emo bands borrowed from some combination of Fugazi, Sunny Day Real Estate, and Weezer. Groups like the Promise Ring, the Get Up Kids, Braid, Texas Is the Reason, Jimmy Eat World, Joan of Arc, and Jets to Brazil earned substantial followings in the indie-rock world, making emo one of the more popular underground rock styles at the turn of the millennium.

I think it's subjective, the definition seems to vary depending on who you talk to. My definition of emo may be different than yours.

I listen to Three Mile Pilot and Bright Eyes, among other bands, and consider them to be emo. But I was talking to one of my cousins and he told me that although he likes these bands, he does not consider them to be emo. He listens to loud, screamy bands that beat the hell out of their instruments, and that's what he considers emo.

The thing is, people categorize bands for easier reference. If I tell you that a band is "heavy metal", for instance, you have a fairly decent idea of what their style of music is. But I consider Black Sabbath to be heavy metal, and a lot of kids nowdays tell me "that isn't heavy at all!".

So I have pretty much given up trying to categorize music. Especially since I listen to a lot of things which are pretty varied and can not be easily categorized. For example, Nick Cave. Just what kind of music is this? Some of his songs are very punk-like, some clearly influenced by the blues, and some of his mellower songs just have no basis for comparison at all. So, when someone asks me "what kind of music does he play", I just say something like "well, you have to hear it, it's pretty varied".

Same thing with Three Mile Pilot, the Black Heart Procession, Pinetop Seven, Lana Lane, all of them among my favorites, but not one of them really fit into an easily defined category or genre.