2. The Primary School Choirs are now preparing for their biggest concert yet, BISB is putting on a huge concert at The Slovak National Radio Building on March 4th. Seven schools will be involved from Bratislava, Budapest and Vienna with over 140 students taking part. It is hoped that this is the first of what will become an annual event, next year we will have to hire a bigger building as demand has been so great! The Bratislava Big Sing 4th March.