Edited sentence: In performance, spectral music often involves little or no use of electronic or computer-generated sound, yet it produces an effect that can sound "electronic" to modern ears, because the precisely calibrated deviations from the normal tunings of notes produce uncanny effects that are normally associated with electronic phenomena such as feedback, ring modulation, frequency modulation, etc.In the general field of computer music, then, spectral music is usually considered "computer assisted composition", rather than "computer generated music" or "electronic music".Individual pieces can be written either electronically (by a computer or playback device delivering sound via speakers); on traditional, non-electronic instruments, requiring specially trained human performers; or a combination of the two methods.This high degree of scientific acoustical sophistication in the performance of new music has become fairly standard in Western Europe but is much less to be found in the United States, where the general cultural conservatism during the same period (the last decades of the 20th century) produced a more relaxed, post-modern, eclectic new music repertoire, casually incorporating elements of commercial and popular music, imitations of historical styles, quotations, pastiche, neoromanticism, diatonic minimalism, etc.To perform such music on traditional instruments such as cellos or clarinets requires an extraordinarily refined training that arose first in France in response to the innovations born at IRCAM