system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do musicians that play in an orchestra have to use sheet music to assist them when other musicians that play other genres of music such as pop and rock etc don’t?
gpt
Length of material, complexity of their part, precision required from each section, specific methodology for learning to perform...just to name a few. 

Besides, it’s not always the case that ensemble and orchestral musicians are reading.