Musical pitch

Ton, m. clay tone sound key tune accent fashion, -art, /. kind of clay key tune (musical) pitch, tonartig, a. clayey, argillaceous. 

The frequency of sound waves is measured in hertz (Hz). Humans have a hearing range from 20 to 20,000 Hz. Another name for the frequency of a sound wave is the musical pitch. Pitches are often referred to as musical notes, such as middle C. 

Krumhansl, C. 1990. Cognitive Foundations of Musical Pitch. Oxford, U.K. Oxford University Press. 

If you punch a few holes along the tube, you alter the frequencies of the standing waves that can form in the tube, with the result that different pitches are produced. This is the underlying principle in such musical instruments as flutes and saxophones. 

QUALITATIVE COMMENTS (with 60 mg) There may well be time slowing. I noticed that the voices on the radio seemed to be of a deeper pitch. And with music there is a most easy flight of fantasy. I tried to keep a logical conversation going on the telephone, but I am pretty s ure there w ere problems. I found myself down sooner than I would have liked. ... 

Another model which is a strong candidate for musical signals is the sinusoidal model, which has been used effectively for speech applications ([McAulay and Quatieri, 1986b] and chapter 9 of this book). A constrained form of the sinusoidal model is implicitly at the heart of short-time spectral attenuation (STSA) methods of noise reduction (see section 4.5.1). The model is also a fundamental assumption of the pitch variation algorithms presented in section 4.6. In its general form the signal can be expressed as ... 

Vaseghi and Rayner [Vaseghi and Rayner, 1990] propose an extended AR model to take account of signals with long-term correlation structure, such as voiced speech, singing or near-periodic music. The model, which is similar to the long term prediction schemes used in some speech coders, introduces extra predictor parameters around the pitch period T, so that equation 4.1 becomes ... 

Consider a fixed-frequency sinusoidal component (/) = sin(wojt + 00 ) from a musical signal, distorted by a pitch variation function p,v(t). The pitch-distorted component x,(t) can be written as (see [Godsill, 1993]) ... 

Numerous commercial instruments were built in the early 1980 s that used asynchronous pitch shifting, including the Fairlight Computer Music Instrument [Roads, 1996], Kurzweil 250 [Byrd and Yavelow, 1986], the E-mu Emulator and Emulator 2 [Massie, 1985], and the New England Digital Synclavier. 

How Many Fractional Phase Register Bits are Needed. The choice of how many bits to make the phase register is an important issue in computer music design. While other authors have covered this issue in relation to traditional sine wave oscillators, there are some subtle differences in the design of sample playback oscillators. Here, the fractional part of the phase register essentially determines how much pitch resolution is available, while the integer part determines how many octaves up the waveform can be transposed (pitch shifted). 

In this procedure it is assumed that musical signals are made up as additive combinations of tones (sinusoids) which represent the fundamental and harmonics of all the musical notes which are playing. Since this is certainly not the case for most non-musical signals, we might expect the method to fail for, say, speech extracts or acoustical noises. Fortunately, it is for musical extracts that pitch variation defects are most critical. The pitch variation process is modelled as a smoothly varying waveform with no sharp discontinuities, which is reasonable for most wow generation mechanisms. 

Post-production Sound Editing In the context of sound recording, the ability to correct the pitch of an off-key musical note can help salvage a take that would otherwise be unusable. Multi-track hard-disk recording machines often offer such capabilities. 

Musical Composition Finally, music composers working with pre-recorded material find it interesting to be given an independent control over time and pitch. In this context, time and pitch-scale modification systems are used as composition tools and the quality of the modified signal is an important issue. 

The time-scale/pitch-scale modification methods presented so far have been used successfully in the domains of speech or music processing. However, a number of problems are almost systematically encountered in practice. 

Sample rate conversion. All of the synchronous pitch shifting techniques essentially involve sample rate conversion techniques. The theory and practice of sample rate conversion has received extensive coverage in many excellent texts and articles, but it is illuminating to compare the computer music perspective with the traditional sample rate conversion literature. Insights from the sample rate conversion literature provide insights to the computer music perspective, and vice versa. 

Drop sample tuning can introduce significant artifacts from changing the pitch of a waveform. This method originated in the design of early computer music oscillators... 

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