[cperciva]

Classical musicians need to sightread, so that pretty much excludes the blind.

Yes and no. I agree that it's very difficult for classical musicians who are completely blind, but there are talented musicians who are legally blind and make use of assistive technology. I know an oboist who plays very well in orchestra despite only being able to see two or three bars of sheet music at a time.

Bands are more manageable because the individuals all have separate lines and are supposed to be listening to each other.

I think the issue is the other way around really. Yes, the musicians in a band all have separate lines, but it's all very coherent -- a melody and some harmony. In symphonic music you might have 24 violinists all playing the same notes, but that's the easy part -- the hard part (and where you really need a conductor) is when one melody is bouncing between the 1st and 2nd violins (with supporting harmonies in the lower strings) while a counter melody is being played by the clarinets and French horns and the trumpets are furiously counting 57 bars of rest before they interrupt in 3/4 time.