You could have a blank sheet to look at and improvise it all and even mess up and I wouldn't notice anything, just the type of music I'd like to perform 😜 I remember when I was a kid and we were having a concert and I got stuck half way through and the audience started applauding and I kept going. I hope my teacher felt more embarrassed than me 🤣
One of the best skills is to keep going and improvise when needed! The score was quite particular but I'm sure there were a few scrapes and buzzes extra! :)