Three evenings a week, children and youths gather at Osawa Toshio's house in Koganei, western Tokyo. They go there to learn nukui-bayashi, a traditional form of music and dance that developed in the first half of the 19th century.

A nukui-bayashi performance has five musicians playing traditional instruments — a flute, a gong, two small drums and a large drum.

I watch as the children start dancing to the music with exaggerated movements, keeping their center of gravity low. Right now they are imitating farmers in old Japan, using hoes to turn over the soil, wringing their sweat out of their hand towels. Later, during a formal performance, they'll wear masks, becoming a dancing jester, moonfaced woman, lion, fox or other creature.

Osawa shouts out sharply, "Hey, get your hips lower! Stretch your arms out all the way, right to your fingertips!"

He explains, "The best thing about hayashi music and dance is that everyone can join in. When the mood rises toward a climax, people in the audience find themselves dancing, too. I want my students' dance and music to be as mesmerizing as that, so I have to be strict about the basics."

The nukui-bayashi style of music and dance began almost 170 years ago, but the genre died out after World War II. Osawa wanted to do something to bring it back to life. He heard that a hayashi style that had branched off from nukui-bayashi was still being practiced in the neighboring city of Fuchu, so he got some friends interested and they went there to learn it. This led to the establishment of the Nukui-bayashi Preservation Society 30 years ago. Since then, Osawa has continued practicing the music and dance with children and other young people three times a week without a break.

Some melodies have been modified and the tempo made faster, to satisfy modern tastes. This is another way to make sure that nukui-bayashi won't disappear again.

"Hayashi music follows the rhythm of the Japanese soul. So as long as we preserve the basics, there's no problem introducing new elements and changing the style a little. After all, hayashi, like every living thing, must adapt."

When I left Osawa's home the music stayed with me — his students were practicing for an upcoming lively performance.

What is hayashi?
Hayashi is a combination of music and dance, originally performed during festivals to welcome the gods and pray for the prosperity of the community. It is still performed in towns and villages throughout Japan. The styles differ from region to region, each one handed down from one generation to the next.