The Swedish 3/4 time slängpolska plays in some strangely danceable world between polka and waltz. This popular example was composed by Uppland herring fisherman, bargeman and renowned nyckelharpist Carl Ersson Bössa (1783-1847), known as Byss-Kalle (or Byss-Calle).
To non-Scandinavian ears, the rhythm is extraordinary: there’s an interesting discussion of slängpolska timing, along with details of Byss-Kalle’s life, at Banjo Hangout here.
Christer Häggmark (fiddle), Urban Andersson (accordion)
Lovely dance-speed rendering played on the hoof at the Delsbostämman festival, Delsbo, Sweden, July 2007.
(‘Slängpolska efter Byss-Kalle’, YouTube video, 2:35. Published by Scan Fiddle, 16 July 2016. https://www.youtube.com/watch?v=HjnSrDsUlcI)
Laurel Swift (fiddle)
Teaching video from Laurel’s West London Folk Band class.
(‘Swedish Polska’, YouTube video, 1:16. Published by Mary Doody, 16 Feb 2016. https://www.youtube.com/watch?v=z7tCRCyB3Iw)
Anahata (melodeon)
(‘Slängpolska efter Byss-Kalle’ – Anahata, melodeon, YouTube video, 2:48. Published by anahatamelodeon, 3 Apr 2016. https://www.youtube.com/watch?v=xJMJpbMzAFQ)
Gig Alert!
Laurel Swift plays double bass and clog dances for ancient/modern folk dance band Gadarene – currently on an their second album launch tour. 
Dates remaining:
Tuesday 25 Oct: Exeter
Friday 28 Oct: London
Friday 4 Nov: Watchet
Friday 25 Nov: Bristol
Details/booking here
Christer Häggmark: Facebook
Urban Andersson: Facebook
Laurel Swift: website Facebook
Laurel’s Ealing workshop videos and sheet music: https://ealingsessions.wordpress.com/
Jenny Glover's FIDDLETAILS 