This chapter deals with several attributes of sounds grossly classified as pitch, along with several associated topics. Stevens et al. developed a scale of pitch as a function of frequency by asking listeners to adjust the frequency of a tone until its pitch was one-half that of another (standard) tone. In addition to their perceptual similarity, two simultaneously presented tones differing by octave intervals are also perceived as being consonant. Timbre enables one to experience differences between sounds having the same pitch, loudness, and duration. The temporal features affecting timbre include such characteristics the amplitude envelope of the waveform (or how amplitude changes over time) and changes in the spectral envelope over time. Timbre perception has also been studied for other sounds as well, such as environmental noises and speech. The ability to account for the timbre of orchestral tones was significantly improved by adding dimensions.