ABSTRACT
This chapter presents the main issues and our solutions to the problem of understanding musical audio signals at the beat level, issues which are common to more general auditory scene analysis. Previous beat tracking systems were not able to work in realistic acoustic environments. We built a real-time beat tracking system that processes audio signals that contain sounds of various instruments. The main features of our solutions are:
To handle ambiguous situations, our system manages multiple agents that maintain multiple hypotheses of beats.
Our system makes a context-dependent decision by leveraging musical knowledge represented as drum patterns.
All processes are performed based on how reliable detected events and hypotheses are, since it is impossible to handle realistic complex signals without mistakes.
Frequency-analysis parameters are dynamically adjusted by interaction between low-level and high-level processing.
