You don’t see The Rolling Stones following a score.  Because they know the music by heart.

That doesn’t make every performance the same.

On the contrary, knowing the ‘original’ by heart means they can play with it, tweak it, customise it in real time for the audience in front of them.

At first, you need a score, so you can share with everyone in the band what needs to happen to make your music.

But the score is the beginning, not the end.