This article deals with the popular and rarely studied art form of manipulating a vinyl record by rhythmically dragging and pushing it, commonly labelled “scratching.” With sufficient practice, a Disc Jockey (DJ) can have great control over the sound produced and treat the turntable as an expressive musical instrument. Even though a digital-based model of scratching might seem preferable to the vulnerable vinyl record, and such models are being manufactured today, the acoustical behaviour of the scratch has not been formally studied until now. To gain information of this behaviour, a DJ was asked to perform some typical scratching patterns. These common playing techniques and the corresponding sounds have been analysed. Since the focus of the article is on the basics of how the instrument works, an overview on standardized equipment and alternative equipment is also given.

The art form of manipulating vinyl records done by disc jockeys (DJs) is called scratching, and has become very popular since its start in the seventies. Since then turntables are commonly used as expressive musical instruments in several musical genres. This phenomenon has had a serious impact on the instrument-making industry, as the sales of turntables and related equipment have boosted. Despite of this, the acoustics of scratching has been barely studied until now. In this paper, we illustrate the complexity of scratching by measuring the gestures of one DJ during a performance. The analysis of these measurements is important to consider in the design of a scratch model.

Scratching performed by a DJ (disk jockey) is a skillful style of playingthe turntable with complex musical output. This study focuses on the description of some of the acoustical parameters and playing strategies of typical scratch improvisations, and how these parameters typically are used for expressive performance. Three professional DJs were instructed to express different emotions through improvisations, and both audio and gesturaldata were recorded. Feature extraction and analysis of the recordings are based on a combination of audio and gestural data, instrument characteristics, and playing techniques. The acoustical and performance parameters extracted from the recordings give a first approximation on the functional ranges within which DJs normally play. Results from the analysis show that parameters which are important for other solo instrument performances, suchas pitch, have less influence in scratching. Both differences and commonalities between the DJs’ playing styles were found. Impact that the findings of this work may have on constructing models for scratch performances arediscussed.

A background on scratching and disc jockey (DJ) interfaces is presented, Skipproof application is described, performance situations where Skipproof is used are presented, and current implementations and possible future uses of Skipproof are discussed. DJing has grown from record players, turntables, and vinyl records to the use of product catalog of commercial physical controllers with other sound formats and sequencer-based interfaces with non-real-time interaction. Skipproof provides the main functionality of a turntable and a mixer, allowing a user to play different sound samples and alter the speed and amplitude manually. Skipproof is used in GUI and visual feedback, sensor and parameter mapping, and audio. The use of radio Baton as the turntable controller in a public performance featuring the Skipproof software showed problems due to the lack of beat synchronization of the scratch techniques and the impossibility of setting a general tempo.

For 30 years Disc Jockeys have been expressing their musical ideas with scratching. Unlike many other popular instruments, the equipment used for scratching is not built as one single unit, and it was not intended to be a musical instrument. This paper gives an overview of how DJs use their turntable, vinyl record and audio mixer in junction to produce scratch music. Their gestural input to the instrument is explained by looking at the mapping principles between the controller parameters and the audio output parameters. Implications are discussed for the design of new interfaces with examples of recent innovations and experiments in the field.

This paper describes an experiment of using an existing hardware platform, the Reactable, to help designing the interaction between three different sound models and instrument interfaces. The aim was to test if prototyping could be facilitated by interacting with models of control actions derivedfrom performance gestures on an intermediate interface. The Reactable isa tangible table-top electronic musical instrument, and the software models include a DJ scratch interface, a virtual turntable, a physics-based sound model representing a bow-and-string interaction, and a physics-based friction sound model for sonification of the user gestures. The interaction was evaluated by two experts: one Reactable musician and one DJ. Their task was to practice expressive, musical performances. Data from the performers were collected through questionnaires and video recordings. The advantages of usinga single, versatile, hardware setup as a designer tool for various interface tasks are discussed. It is suggested how this hardware can be described as an alternative mapping layer.