4 - Intervals and Scales

Abstract

Simultaneous and sequential combinations of pitches are highly meaningful in music. Simultaneous intervals are the basis of harmony; sequential intervals are the basis of melody. Sensory factors constrain preferences for musical intervals, but learning also plays a crucial role. Music illustrates the potential for harmonic and melodic intervals to interact. The capacity to extract changes in pitch direction may be a general property of the auditory system that underlies the perception of both music and speech intonation; whether interval perception is a music-specific skill remains unclear. Our perceptions of the size of pitch intervals are susceptible to a range of extraneous influences such as timbre, pitch register, direction of pitch change, tonal context, and visual signals arising from performers. Knowledge of scales permits precise distinctions between interval sizes. Because scale development depends on instrument timbres, there is no one ideal scale or tuning system. However, most scales throughout history and across cultures are predictable from the harmonic series, reflecting the prevalence of harmonic spectra in musical instruments, including the human voice.