Japanese music is eclectic and diverse. Many instruments, such as the koto, were introduced in the 9th and 10th centuries. The popular folk music, with the guitar-like shamisen, dates from the 16th century. Western classical music, introduced in the late 19th century, forms an integral part of Japanese culture. Kumi-daiko (ensemble drumming) was developed in postwar Japan and became very popular in North America. Popular music in post-war Japan has been heavily influenced by American and European trends, which has led to the evolution of J-pop. Karaoke is a significant cultural activity.