Dubstep is a genre of electronic dance music described as tightly coiled productions with overwhelming bass lines and reverberant drum patterns, clipped samples, and occasional vocals.
Dubstep's early roots are in the more experimental releases of UK garage producers, seeking to incorporate elements of drum and bass into the South London-based 2-step garage sound. The genre's feel is commonly dark; tracks frequently use a minor key and can feature dissonant harmonies such as the tritone interval within a riff. Other distinguishing features often found are the use of samples, a propulsive, sparse rhythm, and an almost omnipresent sub-bass.
Dubstep rhythms are usually syncopated, and often shuffled or incorporating tuplets. The tempo is nearly always in the range of 138-142 beats per minute, with a clap or snare usually inserted every third beat in a bar. In its early stages, dubstep was often more percussive, with more influences from 2-step drum patterns.
One characteristic of certain strands of dubstep is the wobble bass, where an extended bass note is manipulated rhythmically. This style of bass is typically produced by using a low frequency oscillator to manipulate certain parameters of a synthesizer such as volume, distortion or filter cutoff. The resulting sound is a timbre that is punctuated by rhythmic variations in volume, filter cutoff, or distortion. This style of bass is a driving factor in some variations of dubstep, particularly at the more club-friendly end of the spectrum. .