It's maybe not really a concertina because made without any reeds but yesterday I received my Striso duet prototype. The Striso board is a new instrument invented by Piers Titus van der Torren. As it is made with the same Wicky (or Hayden) keyboard than my duet concertina I asked Piers to build this duet version with 2 Striso boards. Here is the first prototype and a first try to play with it the tune Peder Gyes from Harald Haugaard. Recorded on an iPhone without any settings. striso.org