Sikus are typically made from
bamboo shoots, but have also been made from condor feathers, bone, and many other materials. Additionally, different types of bamboo are employed to change the quality of the sound. Songo, or shallow-walled bamboo, gives a louder, more resonant sound than regular deep-walled bamboo, but is less common due to its fragility. The antara are traditionally made from a type of cane known as
chuki or
chajlla (
Arundo donax) that grows in the
ceja de la selva, literally "the eyebrow of the forest". The pipes are held together by one or two strips of cane (ties) to form a trapezoidal plane (like a raft). Antaras are of different sizes and they produce diverse sounds. Siku is split across two rows of pipes. One must alternate rows with every note in order to play a complete scale. Traditionally, two musicians were required to play the siku, each one taking one row of the instrument. One part of the instrument is called
ira, another
arka. It is considered that spiritually
ira corresponds to male principle and
arka to female. When many musicians divide in two parts, first playing
ira and second playing
arka, this gives
Andean music a distinctive
stereophonic sound. Hear [//upload.wikimedia.org/wikipedia/commons/1/16/Kantu.mid example]. Now it is more common to see one musician playing both rows of the instrument together, but rustic ensembles retain traditional playing. == Varieties ==