The four instruments are the kkwaenggwari (a small hand-held gong), the jing (a large hanging gong), the janggu (an hourglass-shaped drum) and the buk (a large barrel drum). In traditional Korean thought, these four instruments together represent rain, wind, thunder and clouds - the sounds of nature and sky.
Samul nori rhythms are built on repeating patterns called 'jangdan'. The musicians listen closely to each other and weave their patterns together, with one player leading changes. The music often starts slowly and softly before speeding up to a furious, joyful climax.
Performers sometimes wear long white ribbons attached to their hats and spin their heads as they play, making the ribbons spiral through the air in beautiful arcs. This tradition comes from farmers' band music performed at harvest celebrations and village festivals.
Samul nori developed from older travelling performer traditions and became widely popular from the 1970s onwards. Today it is taught in schools and performed on concert stages. Children often learn the janggu drum as their first samul nori instrument.