Jöns Lars Fars Polska is a tune that comes to us from the Rättvik fiddler, Röjås Erik Andersson. It refers to the father of a fiddler known as Jöns Lars.
While I am not sure of who this Jöns Lars was, there was a family that used to take the name of a particular farm called Jöns.
In Rättvik there was a Jöns Lars Olsson born in 1775, who died in 1847. It is likely that this is a fiddler who played this tune, calling it his father’s piece.
Here is a YouTube video of the tune being played for dancing by a group called JPP. They are Finnish musicians, but play a lot of Swedish music as well.