Traditional Korean music, called Gugak – literally “national music” – in Korean, is comprised of four broad genres: court, literati, folk and religious. Court and literati music is based on a concept called yeak sasang, which aimed to create harmony via proper behavior, and therefore was expected to be devoid of any emotion. Folk music was, on the contrary, expressive of both positive and negative emotions and varied widely from region to region
A distinguishing feature of Korean music is its standard use of three-four time, as opposed to two-four or four-four time found in Western, Chinese, or Japanese music. It utilizes variations on a pentatonic scale. Rather than harmonizing with chords, Gugak evokes a single melodic line with variations and rhythmic accents to bring out the various instrumental tones. Court, literati, and religious music were unimaginably slow to keep in line with yeak sasang, while folk music could be more expressive and was therefore faster. Folk music, and some literati music, has a strong tradition of improvisation, much like jazz music in the West. Folk music was also a communal experience, with musician and audience interacting throughout the performance.