Dear Simon, thanks for your nice replay. It is a traditional dance tune from Sardinia named "Passu Torrau".
You may find several versions of it on youtube. In the recording I played mandolin, mandola, bouzouki and of course, concertina. Sardinian music is really fascinating and hypnotic.
As well as Irish music it seems simple but, indeed, it is not so easy to play properly and it needs a lot of study.
All the best