Many other musical traditions employ scales that include other intervals or a different number of
pitches. According to Burns (1998, p. 217), the use of discrete pitch relationships is largely universal, pitch
glides (as glissandos or portamentos) are used as embellishment and ornamentation in most musical
cultures, and the concept of octave equivalence, although far from universal in early and structurally
simpler music, seems to be common to more advanced musical systems.