In his autobiography Yehudi admited that he had a huge problem with playing without "the dots". He could not invent "on the fly" and had to know what he was going to play note for note.

I have often seen the same thing as the fiddle/violin difference between English concertina and Anglo concertina players, though it has reduced a lot in recent years. When I used to go to the West Country Concertina meetings we would often finish off with some tunes played en masse. A large proportion of the English players would reach for the music for even the most well known and basic tunes.