I would leave it in English - it is the name of this particular folk music event.

German term (edited): Almerisch

Alm is an German/Austrian alpine pasture (meadow), where cattle are kept during the summer months. A certain style of folk music has developped during the past centuries. So it is something like Songs (gesungen) and Music (gespielt) from the alpine pastures. The belief "Auf der Alm, da gibts koa Sünd" adds to the tones and undertones of this style of music. As a Bavarian I'm extremely reluctant to those music festivals and their economic background. I never understood why zhis kind of activities never have developped among, say, programmers or translators but are restricted to the alpine dairy industry.