Gagok refers to the country’s traditional songs (melodies attached to poems with fixed form) sung to orchestral accompaniment. Present-day gagok were derived from Sakdaeyeop, which refers to fast melodies of music that first appeared in the late Joseon Period. The number of gagok that are still sung stands at 41 (26 sung by male singers and 15 sung by female singers). They are accompanied by geomungo (six-stringed zither), gayageum (twelve-stringed zither), haegeum (two-stringed fiddle), daegeum (bamboo flute), danso (vertical notched flute), and janggo (hourglass-shaped drum) in a highly organized fashion. Gagok have been maintained well for a long period. Unlike other popular pieces of music, gagok have been handed down by experts as those with high artistic value.