appears from the variety of semitone instruments found in indigenous groups throughout Peru that indigenous music is not solely pentatonic. Other panpipe varieties, associated with specific tribes, include the oribe (Witoto tribal group), urusa (Omagua group), jonkari (Ashaninka/Campa), and antaras (Quechua).
Both Aymara and Quechua musical elaborations are said to be acculturated with dominant European musical forms, with Quechua forms the more influential.5 Some ethnomusicologists have lamented the decline of the distinctive style of Andean music, speculating that the marked social disadvantages of the indigenous groups have aggravated the problem: "Perhaps the frustration affecting the Aymara as a people debilitates their music."6 Chacon identifies the siku equally with Quechua and Aymara, both of which are situated in the Altiplano,7 and considers the siku and the musical forms associated with to be not only a dominant remnant of indigenous culture but also the agent of the expansion of Andean music. As for the pentatonic scale, Chacon asserts that the Altiplano siku in use today can approximate and is tuned to the diatonic scale, which is typical of Western European music, but adds it reaches chromatic intervals between diatonic tones. Further, he says, Andean diatonic modes are not necessarily derived from European diatonicism. Finally, he associates Andean music with a heptaphonic scale, inasmuch as the music that is typically played on sikus fails within heptaphonic tonal range.8
The bipolar siku is a term that Chacon9 derives from the technical and structural characteristics of the instrument in its contemporary configuration. It is of seven-tube raft rather than bundled construction, which means that its tubes, which are of different lengths and diameters, are strapped together on one plane. However, planes may be fastened in multiple rows (even numbers of rows are typical). The primary row or rows are meant ...