MUSIC SIGNAL ANALYSIS
37.1 THE INFORMATION IN MUSIC AUDIO
Music is arguably the richest and most carefully-constructed of all acoustic signals – several highly-trained performers can work for hours to get the precise, desired effect in a particular recording. We might conclude that the information carried by the musical waveform is greater than in any other sound – although this immediately gets us into the puzzling territory of trying to define exactly what information it is that music carries, why it exists, and why so many people spend so much time creating and enjoying it.
Leaving aside those philosophical points that are beyond the scope of this chapter, we can easily name a great many objective aspects of a music recording that a listener can extract, with more or less difficulty, such as the beat, melody, lyrics etc. As with other perceptual feats, we can hope to build computer-based systems to mimic these abilities, and it is interesting to see how successful such approaches can be, and to consider the applications in which such automatic systems could be used.
As discussed in Chapter 36, music has been linked to computers since the earliest days of electronic computation, including Max Matthews’ 1967 synthesis of “Daisy Daisy” on an IBM 7094. Computer music synthesis soon led to the idea of computer music analysis, with the first attempt at automatic transcription ...