Why can bands play for hours often utilizing different instruments without ever looking at sheet music, but orchestra musicians always read from sheet music?

Question

I saw a clip where a pianist was playing and someone was turning her pages for her, but they fumbled and dropped the sheet music. The pianist kept on playing, but it got me wondering why have the sheet music if she knows the song anyway. Do they really need it? Why can’t they just learn the songs like all bands do?

In: 5311

Answer 1

There are already some great answers here. I’ll try to give a short one.

When you are listening to an orchestra, they are attempting to collectively play a piece exactly as it was intended by composers and arrangers. When you are listening to a band, they are playing something the way they want to play it, and perhaps even of their own composition. It is entirely up to them what it sounds like, and in many cases improvisation is encouraged.