Dub music is characterised by a ‘version’ or ‘double’ of an existing song, often instrumental, using B-sides of 45 RPM records and typically emphasizing the drums and bass for a sound popular in local sound systems. The instrumental tracks are typically drenched in sound effects such as echo, reverberation, with instruments and vocals dropping in and out of the mix. The music sometimes features other noises, such as birds singing, thunder and lightning, water flowing, and producers shouting instructions at the musicians. It is often further augmented. The many-layered sounds with varying echoes and volumes are often said to create soundscapes, or sound sculptures. There is usually a distinctly organic feel to Dub music, even though the effects are often electronically created. Enjoy Stems' Dub Music, "DUB MATTRESS"