This Springvals från Valö is an excellent example of a special kind of waltz.
The most common kind of waltz in the Swedish fiddle tradition is the stegvals. It is a medium-paced dance of even tempo. The springvals, or running waltz, is much faster, and danced with very small steps. While the springvals may be found in many areas of Sweden, it is most common in Uppland.
This tune is from the nyckelharpa and fiddle traditon of the Wallin family, and especially connected to the harpa player Ceylon Wallin. He grew up in the area near the little town of Valö, and learned many tunes from his father, Albin Wallin.
Here is a YouTube recording of Ceylon playing this Springvals.
To the left is a video of me playing it on the fiddle.