The past Medieval Fair in Vrana was interesting for various folklore elements presented: everything from local food and customs to traditional singing.
The singers were local women and men who learned the tradition from their fathers. The singing was popular at celebrations and manifestations and was usually preformed without instruments. From the original singing, popular a capella, klapa singing evolved.
Listen to the traditional song performed in Vrana:
Great tradition, but less in North Dalmatia are diple. This instrument is quite similar to bag-pipes and probably have the same origin in the ancient European traditions.
There is a wonderful documentary (in Croatian) on the folklore traditions of diple and traditional dancing.