In the middle of the last 'part' we were playing I see a little note 'Pic' - which means, 'Change to Piccolo'. Its common enough on flute music as with orchestral music (such as this piece) its expected that one of the two flute players will also play the piccolo (it is my plan to buy one at some point).
I couldn't change so carried on playing. A couple of bars later I saw the reason why. The notes were so high I couldn't workout which note they were - even less attempt at playing them.
Such is the fun of music your're not used to. I've played the piece before - but it was on a clarinet - which is very different.