Tswee faKh er
The Zwiefacher is an Alpine dance form that is documented in Bavaria in the 1400's and is still popular today. It consists of mixed rhythm melodies, usually in Waltz and March time. Tunes have different mixtures of patterns and bands play the music with more differences. Thus; these dances range in difficulty from "a bit tricky", the simpliest, to nearly "perverse".
Follow this link to a file of Zwiefacher directions. You will need a pdf file viewer, like Acrobat, to view it.
Follow this link to a web page holding over 200 Zwiefacher patterns as recorded on over 40 recordings.