Österbybruk is the oldest iron making estate in Uppland. There was a smelting works here in 1443, and a blast furnace and hammers at the beginning of the 16th century.

The manor house, were the nyckelharpstämma takes place, with its wings is from the 1760s, as are the grounds, the Walloon forge and the smiths’ housing. Bruno Liljefors’s studio is used at the spelmansstämma for the singing gathering where everyone join in - or takes up a song to lead the rest.

Two days with playing everywhere, dancing, concerts, courses, competitions and much more. If you play/dance your self or a tourist who want to see one of the best, and perhaps exotic, side of the Swedish summer and culture: Do not miss this event!

On Sunday there is also an exhibition of lots of new built and some old nyckelharpas.

The Sunday stämma begins with the players marching through the village.

The nyckelharpa - The National Music Instrument of Sweden - originates from the area around the Baltic Sea. It has been in existence ever since the Middle Ages. Most of the evidence for the instrument in early times comes from Sweden. The last four hundred years up to the end of the 20:th century it seems to have been played almost exclusively in Uppland, the province north of Stockholm. Now the American Nyckelharpa Association has about 150 members, and there are nyckelharpa players in Switzerland, France, England and a few other countries

The first Nyckelharpa World Championships took place in Österbybruk 16-17 June 1990, and the first nyckelharpa championship for youth players was held in 1999.