Score-informed and timbre independent lead instrument separation in real-world scenarios

We present a method for lead instrument separation using an available musical score that may not be properly aligned with the polyphonic audio mixture. Improper alignment degrades the performance of existing score-informed source separation algorithms. Several techniques are proposed to manage local and global misalignments, such as a score information confidence measure, and a chroma based MIDIaudio alignment. The proposed separation approach uses time-frequency masks derived from a pitch tracking algorithm, which is guided by the MIDI file´s main melody. Timbre information is not needed in the present approach. An evaluation conducted on a custom dataset of stereo convolutive audio mixtures showed significant improvement using the proposed techniques compared to the non score-informed separation.