Musical extrapolation of speech with auto-DJ

In recent years, personalized mobile phone ringtones have been in growing demand. This paper describes auto-DJ, which uses the phone owners' voices in software DJ's performances for creating their own personalized ringtones, with a focus on its scratched sound synthesis module. Scratching is the primary technique for playing the turntable as a musical instrument - making "new" sounds from records by changing the rate of playing them with hand movements. A scratched sound synthesizer turns sound clips into scratches, each of which comprises one or more strokes. We synthesize them by resampling using pitch deviation envelopes which are derived from those matched for original scratched sounds. Our score representation allows musicians to describe scratches, strokes, and their acoustic characteristics in a musical and concise notation. The scratched sound synthesizer currently produces three types of scratches. Despite the small repertoire, we have successfully created realistic and expressive performances.