Hi Jack, we were there a few years ago and there was a music shop not far from the Ramblas - I remember one of the lads bought a Gralla.

My Sac De Gemecs story for your delight. There is no clack valve, and a local (Sheffield) lad asked a Sac de Gemecs player if he could have a go. Since my Catalan did not stretch to "tell him there is no clack valve" I couldn't translate what the Catalan was trying to tell me. Thus the Sheffield lad nearly blew himself up and sail over the town hall.