Score-Informed Source Separation for Musical Audio Recordings: An overview

In recent years, source separation has been a central research topic in music signal processing, with applications in stereo-to-surround up-mixing, remixing tools for disc jockeys or producers, instrument-wise equalizing, karaoke systems, and preprocessing in music analysis tasks. Musical sound sources, however, are often strongly correlated in time and frequency, and without additional knowledge about the sources, a decomposition of a musical recording is often infeasible. To simplify this complex task, various methods have recently been proposed that exploit the availability of a musical score. The additional instrumentation and note information provided by the score guides the separation process, leading to significant improvements in terms of separation quality and robustness. A major challenge in utilizing this rich source of information is to bridge the gap between high-level musical events specified by the score and their corresponding acoustic realizations in an audio recording. In this article, we review recent developments in score-informed source separation and discuss various strategies for integrating the prior knowledge encoded by the score.