Hawthorne Heights in the context of "Hot Modern Rock Tracks"

Emo (/ˈiːmoʊ/ EE-moh) is a genre of rock music that combines musical characteristics of hardcore punk with emotional, often confessional lyrics. It emerged as a style of hardcore punk and post-hardcore from the mid-1980s Washington, D.C., hardcore scene, where it was known as emotional hardcore or emocore. The bands Rites of Spring and Embrace, among others, pioneered the genre. In the early-to-mid 1990s, emo was adopted and reinvented by alternative rock, indie rock, punk rock, and pop-punk bands, including Sunny Day Real Estate, Jawbreaker, Cap'n Jazz, Mineral, and Jimmy Eat World. By the mid-1990s, Braid, the Promise Ring, American Football, and the Get Up Kids emerged from Midwest emo, and several independent record labels began to specialize in the genre. Meanwhile, screamo, a more aggressive style of emo using screamed vocals, also emerged, pioneered by the San Diego bands Heroin and Antioch Arrow. Screamo achieved mainstream success in the 2000s with bands like Hawthorne Heights, Silverstein, Story of the Year, Thursday, the Used, and Underoath.

The emo subculture signifies a specific relationship between fans and artists and certain aspects of fashion, culture, and behavior. Emo fashion includes skinny jeans, black eyeliner, tight t-shirts with band names, studded belts, and flat, straight, jet-black hair with long bangs. Since the early-to-mid 2000s, fans of emo music who dress like this are referred to as "emo kids" or "emos". The emo subculture was stereotypically associated with social alienation, sensitivity, misanthropy, introversion, and angst. Purported links to depression, self-harm, and suicide, combined with its rise in popularity in the early 2000s, inspired a backlash against emo, with some bands, including My Chemical Romance and Panic! at the Disco, rejecting the emo label because of the social stigma and controversy surrounding it. There has long been controversy over which bands are labeled "emo", especially for bands that started outside traditional emo scenes; a viral website, Is This Band Emo?, was created to address one fan's opinion on this question. Emo and its subgenre emo pop entered mainstream culture in the early 2000s with the success of Jimmy Eat World and Dashboard Confessional, and many artists signed contracts with major record labels. Bands such as My Chemical Romance, AFI, Fall Out Boy, and the Red Jumpsuit Apparatus continued the genre's popularity during the rest of the decade.

Post-hardcore is a punk rock music genre that maintains the aggression and intensity of hardcore punk but emphasizes a greater degree of creative expression. Like the term "post-punk", the term "post-hardcore" has been applied to a broad constellation of groups. Initially taking inspiration from post-punk and noise rock, post-hardcore began in the 1980s with bands like Hüsker Dü and Minutemen. The genre expanded in the 1980s and 1990s with releases by bands from cities which had established hardcore scenes, such as Fugazi from Washington, D.C. as well as groups such as Big Black, Jawbox, Quicksand, and Shellac who stuck closer to post-hardcore's noise rock roots. Dischord Records became a major nexus of post-hardcore during this period.

The genre also began to incorporate more dense, complex, and atmospheric instrumentals with bands like Slint and Unwound, and also experienced some crossover from indie rock with bands like The Dismemberment Plan. In the early- and mid-2000s, post-hardcore achieved mainstream success with the popularity of bands like At the Drive-In, My Chemical Romance, Dance Gavin Dance, AFI, Underoath, Hawthorne Heights, Silverstein, the Used, Saosin, Alexisonfire, and Senses Fail. In the 2010s, bands like Sleeping with Sirens and Pierce the Veil achieved mainstream success under the post-hardcore label. Meanwhile, bands like Title Fight and La Dispute experienced underground popularity playing music that bore a closer resemblance to the post-hardcore bands of the 1980s and 1990s.