From raw audio to a seamless mix: creating an automated DJ system for Drum and Bass

Len Vande Veire,Tijl De Bie

doi:10.1186/s13636-018-0134-8

Abstract

We present the open-source implementation of the first fully automatic and comprehensive DJ system, able to generate seamless music mixes using songs from a given library much like a human DJ does.The proposed system is built on top of several enhanced music information retrieval (MIR) techniques, such as for beat tracking, downbeat tracking, and structural segmentation, to obtain an understanding of the musical structure. Leveraging the understanding of the music tracks offered by these state-of-the-art MIR techniques, the proposed system surpasses existing automatic DJ systems both in accuracy and completeness. To the best of our knowledge, it is the first fully integrated solution that takes all basic DJing best practices into account, from beat and downbeat matching to identification of suitable cue points, determining a suitable cross-fade profile and compiling an interesting playlist that trades off innovation with continuity.To make this possible, we focused on one specific sub-genre of electronic dance music, namely Drum and Bass. This allowed us to exploit genre-specific properties, resulting in a more robust performance and tailored mixing behavior.Evaluation on a corpus of 160 Drum and Bass songs and an additional hold-out set of 220 songs shows that the used MIR algorithms can annotate 91% of the songs with fully correct annotations (tempo, beats, downbeats, and structure for cue points). On these songs, the proposed song selection process and the implemented DJing techniques enable the system to generate mixes of high quality, as confirmed by a subjective user test in which 18 Drum and Bass fans participated.

Highlights

When music tracks are played back to back, i.e., starting one song after the other is finished, the listening experience is interrupted between the end of a song and the beginning of the
5 Results and discussion The automatic Disk jockey (DJ) system has been tested on different aspects
6 Conclusions The automatic DJ system presented in this paper generates a seamless music mix from a library of Drum and Bass songs

Summary

Introduction

When music tracks are played back to back, i.e., starting one song after the other is finished, the listening experience is interrupted between the end of a song and the beginning of the next. The system is, to the best of the author’s knowledge, the first complete and fully integrated automatic DJ system that considers all basic DJing best practices, i.e., beatmatching, cue point selection, music style-based track selection, equalization, and different transition types. It is released as open-source1and could serve as a robust basis for further research to build upon. Two types of systems reoccur in the scientific literature: automatic DJ systems and mash-up systems (Table 1) The former attempt to automate (parts of ) the DJing task, i.e., create a continuous mix by smoothly transitioning between songs. In what follows is described how the proposed DJ system extracts the beat, downbeat, and segment boundary locations from the audio in a hierarchical way given the assumptions listed above

Beat tracking

Results and discussion

User study: evaluation of the musical style descriptor and system evaluation

Conclusions