Topic on Dubstep, which is a genre of music. 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. These experiments often ended up on the B-side of a white label or commercial garage release. Dubstep is generally instrumental. Similar to a vocal garage hybrid - grime - 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. Some dubstep artists have also incorporated a variety of outside influences, from dub-influenced techno such as Basic Channel to classical music or heavy metal.