THE USE OF RECURSIVE MEDIAN FILTERS FOR ESTABLISHING THE TONAL CONTEXT IN MUSIC
Ilya Shmulevich, Edward J. Coyle · 1998
The recursive median filter is used to improve the structure of the output of the key finding algorithm for establishing tonal contexts of musical patterns in a musical composition. This is subsequently incorporated into a system for recognition of musical patterns. Krumhansl's key-finding algorithm is used as a basis. The sequence of maximum correlations that it outputs is smoothed with a cubic spline and is used to determine weights for perceptual and absolute pitch errors. Maximum correlations are used to create the assigned key sequence, which is processed by a recursive median filter. In most cases, the recursive median filter establishes the key more accurately than the standard median filter. Additionally, since the recursive median is idempotent, the key-finding output is guaranteed to be a root signal. INTRODUCTION Musical Pattern Recognition (MPR) is concerned with recognition or classification of musical patterns. Figure 2 shows a block diagram of the MPR system. It produc...