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

Musician here (with experience in both a band and an orchestra),
Bands often play a similar set wherever they go, so naturally they have more time to learn a song without relying on sheets. They are also (usually) much more loose when it comes to the arrangement of the music, and having fewer musicians means it’s easier to just agree what they’re playing and how it should be played.

Orchestras tend to change their material much more often, meaning they use sheet music as a quicker way of getting everyone up to speed – especially important since they’re often larger ensembles than bands and can’t communicate with each musician as easily as a band. Orchestral music is also pretty intricate, so knowing exactly what you’re supposed to do (as well as a reference for following the conductor) is often required. People usually expect orchestras to play the piece exactly right, whereas bands are more free to make changes to the arrangement.