Drum and bass (/ˈdrʌm ənd ˈbeɪs/) (also written as drum 'n' bass and commonly abbreviated to D&B, D+B or DnB) is a type of electronic music which emerged in the mid 1990s. The genre is characterized by fast breakbeats (typically between 160–180 bpm, occasional variation is noted in older compositions), with heavy bass and sub-bass lines. Drum and bass began as an offshoot of the United Kingdom rave scene of the very early 1990s. Over the first decade of its existence, the incorporation of elements from various musical genres led to many permutations in its overall style.
In the late 1980s and early 1990s, a growing nightclub and overnight outdoor event culture gave birth to a new electronic music style called rave music, which, much like hip-hop, combined sampled syncopated beats or breakbeats, other samples from a wide range of different musical genres and, occasionally, samples of music, dialogue and effects from films and television programmes. But rave music tended to feature stronger bass sounds and a faster tempo (127 to over 140) beats per minute (BPM) than that of early house music. This subgenre was known as "hardcore" rave but from as early as 1992, some musical tracks made up of these high-tempo break beats, with heavy basslines and samples of older Jamaican music, were referred to as "jungle techno" and later just "jungle", which became recognised as a separate musical genre popular at raves and on pirate radio in Britain. It is important to note when discussing the history of Drum n Bass that prior to Jungle, rave music was getting faster and more experimental. Professional DJ & producer C.K. states, "There was a progression as far as the speed of music is concerned. Anyone buying vinyl every week from 1989 to 1992 noticed this."
By 1994 jungle had begun to gain mainstream popularity and fans of the music (often referred to as junglists) became a more recognisable part of British youth subculture. The genre further developed, incorporating and fusing elements from a wide range of existing musical genres, including the raggamuffin sound, dancehall, MC chants, dub basslines, and increasingly complex, heavily edited breakbeat percussion. Despite the affiliation with the ecstasy-fuelled rave scene, Jungle also inherited some associations with violence and criminal activity, both from the gang culture that had affected the UK's hip-hop scene and as a consequence of jungle's often aggressive or menacing sound and themes of violence (usually reflected in the choice of samples). However, this developed in tandem with the often positive reputation of the music as part of the wider rave scene and dancehall-based Jamaican music culture prevalent in London. Whether as a reaction to, or independently of this cultural schism, some jungle producers began to move away from the ragga-influenced style and create what would become collectively labelled, for convenience, as drum and bass.
As the genre became generally more polished and sophisticated technically, it began to expand its reach from pirate radio to commercial stations and gain widespread acceptance (circa 1995–1997). It also began to split into recognizable subgenres such as jump-up and Hardstep. As a lighter and often jazz-influenced style of drum and bass gained mainstream appeal, additional subgenres emerged including techstep (circa 1996–1997) which drew greater influence from techno music and the soundscapes of science fiction and anime films.
The popularity of drum and bass at its commercial peak ran parallel to several other homegrown dance styles in the UK including big beat and hard house. But towards the turn of the millennium its popularity was deemed to have dwindled as the UK garage style known as speed garage yielded several hit singles. Speed garage shared high tempos and heavy basslines with drum and bass but otherwise followed the established conventions of "house music", with this and its freshness giving it an advantage commercially. London DJ/producer C.K. says, "It is often forgotten by my students that a type of music called "Garage House" existed in the late 1980s alongside Hip House, Acid House and other forms of House music." He continues, "This new Garage of the mid 90s was not a form of House or a progression of Garage House. The beats and tempo that define House are entirely different. This did cause further confusion in the presence of new House music of the mid 1990s being played alongside what was now being called Garage." Despite this, the emergence of further subgenres and related styles such as liquid funk brought a wave of new artists incorporating new ideas and techniques, supporting continual evolution of the genre. To this day drum and bass makes frequent appearances in mainstream media and popular culture including in television, as well as being a major reference point for subsequent genres such as grime and dubstep and successful artists including Chase & Status and Australia's Pendulum.
...more info at http://en.wikipedia.org/wiki/Drum_and_bass