Drum and bass (commonly abbreviated to D&B, DnB, dnb, d'n'b, drum n bass, drum & bass, dNb, deebee, D+B, d+b, DNB, d and b, D and B), is a type of electronic dance music which emerged in the mid 1990s. The genre is characterized by fast breakbeats (typically between 160–190 bpm, occasional variation is noted in older compositions), with heavy bass, sub-bass lines, and occasional infra-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 lent to many permutations in its overall style.