The Farmer Germund is planning a wedding between his daughter Marit and Mats, the son of a neighboring farm. Everything seems to be going according to plan until Marit meets the fiddler Jon, an illegitimate son who enchants the youth with his violin.
Based on Evert Taube songs about the sailor and womanizer Fritiof Andersson. Midsummer in the archipelago of Roslagen. Andersson has returned home to settle down with his fiancee Linnea. On the dance floor he meets Rosa.