1) Tref is a Belgian folkgroup, with the diatonic button accordion (in Dutch/Flemish: "trekzak") as their main instrument.

members:

Diatonic button accordion:
* Wim Claeys
* Didier Laloy
Percussion and Berimbau:
* Frédéric Malempré

2) Treff is a hard rock band from Hungary. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.