Music is different from speech in that its role is not so much to convey linguistic and conceptual content – although it may have this role also – as it is to evoke an aesthetic and emotional experiences. Both speech and music are sort of ‘utility’ sounds that are experienced mostly with a ‘positive’ attitude, although in some circumstances they may become annoying or disturbing: noise.
In addition to speech, music is the second major form of acoustic communication between humans. The psychoacoustics of intervals and melodies in music will be discussed later in this book in Section 11.6. We begin with the discussion of the formation of sounds in acoustical and electric musical instruments in this section.
Acoustic instruments generate a large set of different sounds (Fletcher and Rossing, 1998). If electroacoustic and electric instruments are also accounted for, the discriminable set of different instrument sounds is, in practice, infinite. However, most music and speech is composed of a limited set of types and structures of sounds, where certain basic properties hold. For example, woodwind or plucked string instruments form distinguishable families of musical instruments, where the principle of sound generation and the structure of the sound signal are similar within each family. We will discuss shortly some basic properties of acoustic and electric instruments and their sounds.