Dub derives its name from the practice of dubbing instrumental, rhythm-oriented versions of reggae songs onto the B-sides of 45 rpm singles, which evolved into a legitimate and accepted style of its own as those re-recordings became forums for engineers to experiment with the possibilities of their mixing consoles. The practice of re-recording reggae tracks without vocals dated back to 1967, when DJs found that dancehall crowds and partygoers greatly enjoyed being given the opportunity to sing the lyrics themselves. Around 1969, some DJs began talking, or "toasting," over these instrumentals (known as "versions"), frequently reinterpreting the already familiar original lyrics. The most important early DJ was U-Roy, who became renowned for his ability to improvise dialogues with the recorded singers; U-Roy ran the sound system owned by engineer King Tubby, who mixed all of the instrumental tracks over which his DJ toasted. Eventually, Tubby began to experiment with remixing the instrumental tracks, bringing up the level of the rhythm section, dropping out most or all of the vocals, and adding new effects like reverb and echo. The results were seen by many reggae fans as stripping the music down to its purest essence. 45-rpm singles with dub versions on the B-sides became ubiquitous, and King Tubby's credit on the back soon became a drawing card in and of itself. Full-fledged dub albums began to appear in 1973, with many highlights stemming from Tubby's mixes for producers Bunny Lee and Augustus Pablo (the latter of whom also played the haunting melodica, which became one of dub's signature added elements); other key early producers included the minimalistic Keith Hudson and the colorful, elaborate Lee "Scratch" Perry. By 1976, dub's popularity in Jamaica was second only to Rastafarian roots reggae, and the sound had also found acceptance the U.K. (thanks largely to the Island label), where roots reggae artists like Burning Spear and Black Uhuru became just as well-known for their forays into dub. The Mad Professor and the experimental Adrian Sherwood helped Britain's dub scene remain vital in the '80s, but in spite of skilled newcomers like Scientist, Prince Jammy, and Mikey Dread, Jamaican popular taste had by then shifted to DJ toasters and lyrical improvisers, which led to the prominence of dancehall and ragga. The downtempo atmospherics and bass- and rhythm-heavy textures of dub had a lasting influence outside of reggae, beginning with Public Image Ltd.'s 1979 Metal Box/Second Edition album; during the '90s, dub was frequently incorporated into the melting-pot eclecticism of underground avant-garde rock, and Britain's thriving electronica/drum'n'bass scene owed a great deal to dub's mixing and production techniques.