Pitch is that quality of sound which allows us to play musical melodies. Naive introductory neuroscience texts tend to equate pitch with frequency. However, most real world sounds contain many frequency components, but have either only one clear pitch, or no pitch at all. Chapter 3 of "Auditory Neuroscience" describes the characteristics of sound that determine pitch, outlines how musical pitch is treated in western classical music, and describes how the brain is thought to extract physical cues to the periodicity of a sound to create the subjective percept of pitch. The following collection of web pages provide supplementary materials to accompany that chapter.
Making sense of sound