Metalcore
Metalcore is a musical genre consisting of a mix between heavy metal and hardcore. Although the genre has risen in popularity since the turn of the millennium, it is not a recent genre, as many would believe, since bands such as Integrity have been around since the late 1980s. Defining the metalcore sound is not an easy task as bands have often fused hardcore-influenced sound and attitude with almost any imaginable type of metal. In fact, the earliest signs of this genre before a name could be put to it was called 'crossover'. The band that declared the crossover was Dirty Rotten Imbeciles on their late 1980's album of the same name. Other bands like Nuclear Assault are the bleeding edge pioneers themselves.
The early scene
Nuclear Assault was amongst the first to call their music a Heavy Metal-Hardcore Punk Hybrid. Although not thought of as a metalcore band today, Judge was arguably one of the earliest bands to start fusing heavy metal-influenced riffing with more traditional hardcore sound without being a thrash metal band. This idea obviously spread outwards, and although their first real release ("Those Who Fear Tomorrow") wasn't until 1991, "Integrity" was formed in 1989. Most songwriting by metalcore bands at this time was similar to New York hardcore bands, but differed in their harder sound thanks to use of double bass drums, harder distortion and louder, more gruff vocal shouts. This basic sound of metalcore has received the epithets - which can be used both with and without derision - "tough guy hardcore" due to the lyrical focus, which is often similar to older hardcore in that they call for moral and mental strength and integrity, but may also have a slight focus on violence, or "moshcore" due to the often breakdown-centric, mosh-friendly songwriting that some bands use.
During the middle of the 1990s, bands started expanding the metalcore sound, prime examples being All Out War who used straightforward thrash riffing, as well as bands such as Rorschach, Starkweather, Orange County's Adamantium, and Deadguy, who experimented with looser, often discordant songwriting as well as more untraditional rhythm. Converge, although starting out as self-confessed "hardcore kids with leftover Slayer riffs", have since bloomed into a hybrid of hardcore, metal and progressive instrumental and electronic experimentation. Zao is another band that left a mark upon the genre with their Carcass-like vocals and varied songwriting, particularly the Christian bands of the genre.
The later scene
From the late 1990s and particularly after the turn of the millennium, metalcore has grown immensely, to the point where major record companies are taking interest in the genre. Recent (2005) releases, such as Lamb Of God's "Ashes Of The Wake" and Norma Jean's "O' God, the Aftermath" have managed to sell well enough to make it onto Billboard charts.
One sound that has become immensely popular is to mix Gothenburg melodic death metal, popularized by more traditional metal bands such as At the Gates, and In Flames and newer bands such as Children of Bodom, together with a more traditional metalcore sound and occasionally slow, melodic breakdowns. Today, many famous metalcore bands play this style, such as The Conflict Theory, Killswitch Engage, The Agony Scene, As I Lay Dying,Unearth, and Lamb Of God
Some bands, such as Botch, expanded on the blueprints of Rorschach and Deadguy, bringing forth intense mathematic influenced guitar riffs, as well as songs. This style is popularized by few recent bands.
The breakdown
Central to many bands of the genre, quite a few of which eschew traditional verse-chorus-verse songwriting, is the breakdown (also known as beatdown). Stereotypically, a breakdown consists of slowing a song down, giving the guitars room to play a set of rhythmically oriented riffs, usually on open strings so as to achieve the lowest sound for which the guitars are tuned. These riffs are often accented by the drummer through double bass drums. Breakdowns are usually responded to by an audience by hardcore dancing. Vocalists also tend to throw in a single, repeated statement throughout the breakdown, giving those who are not dancing an opportunity to sing along. Many metalcore bands rely on having memorable breakdowns rather than memorable choruses. Songs with breakdowns have become more common, and some bands have used them far more often than was previously the norm, with some songs even resembling one elongated breakdown.