Scratching

Scratching, sometimes referred to as scrubbing, is a DJ and turntablist technique of moving a vinyl record back and forth on a turntable to produce percussive or rhythmic sounds. A crossfader on a DJ mixer may be used to fade between two records simultaneously.
While scratching is most associated with hip hop music, where it emerged in the mid-1970s, from the 1990s it has been used in some styles of rap rock, rap metal and nu metal. In hip hop culture, scratching is one of the measures of a DJ's skills. DJs compete in scratching competitions at the DMC World DJ Championship and IDA (International DJ Association, formerly known as ITF (International Turntablist Federation). At scratching competitions, DJs can use only scratch-oriented gear (turntables, DJ mixer, digital vinyl systems or vinyl records only). In recorded hip hop songs, scratched "hooks" often use portions of other songs.
Subculture.
While scratching is becoming more and more popular in pop music, particularly with the crossover success of pop-hip hop tracks in the 2010s, sophisticated scratching and other expert turntablism techniques are still predominantly an underground style developed by the DJ subculture. The Invisibl Skratch Piklz from San Francisco focuses on scratching. In 1994, the group was formed by DJs Q-Bert, Disk &amp; Shortkut and later Mix Master Mike. In July 2000, San Francisco's Yerba Buena Center for the Arts held Skratchcon2000, the first DJ Skratch forum that provided “the education and development of skratch music literacy”. In 2001, Thud Rumble became an independent company that works with DJ artists to produce and distribute scratch records.
In 2004, "Scratch Magazine", one of the first publications about hip hop DJs and record producers, released its debut issue, following in the footsteps of the lesser-known "Tablist" magazine. Pedestrian is a UK arts organisation that runs Urban Music Mentors workshops led by DJs. At these workshops, DJs teach youth how to create beats, use turntables to create mixes, act as an MC at events, and perform club sets.
Use outside hip hop.
Scratching has been incorporated into a number of other musical genres, including pop, rock, jazz, some subgenres of heavy metal (notably nu metal) and some contemporary and avant-garde classical music performances. For recording use, samplers are often used instead of physically scratching a vinyl record.
DJ Product©1969, formerly of the rap rock band Hed PE, recalled that the punk rock band the Vandals was the first rock band he remembered seeing use turntable scratching. Product©1969 also recalled the early rap metal band Proper Grounds, which was signed to Madonna's Maverick Records, as being another one of the first rock bands to utilize scratching in their music.
Guitarist Tom Morello, known for his work with Rage Against the Machine and Audioslave, has performed guitar solos that imitate scratching by using the kill switch on his guitar. Perhaps the best-known example is "Bulls on Parade", in which he creates scratch-like rhythmic sounds by rubbing the strings over the pick-ups while using the pickup selector switch as a crossfader.
Since the 1990s, scratching has been used in a variety of popular music genres such as nu metal, exemplified by Linkin Park, Slipknot and Limp Bizkit. It has also been used by artists in pop music (e.g. Nelly Furtado) and alternative rock (e.g. Incubus). Scratching is also popular in various electronic music styles, such as hard-groove techno.