> Welcome to live music baby.

Thanks? I’ve been doing this job for more than a decade at this point.

> Most bands play for hours at a time without the accompaniment or sheet music. All in the noggin.

The difference between “most bands” and a professional symphony orchestra is that most bands have a repertoire of a few dozen songs which they memorize and play again and again. It’s easy to memorize things when you play the same few repeatedly.

But professional orchestras learn 1-3 new concerts worth of music every week. If it’s a big masterworks week, we probably only learn one set of music. Like an overture, concerto, and a symphony. But in some weeks we might play a kids show, then a light classics concert, then a pops concert all in the same week.

So a masterworks schedule might look like 5 rehearsals and 3 concerts of all the same music in a week. Then we are done with that music and doing something else the next week.

A busier week might be one rehearsal and one concert of kids show music, then the next day two rehearsals of light classics, then the following day two light classics concerts, then the following day a pops rehearsal and concert, then the last day two more pops concerts. So that’s 3 sets of music we’ve learned all within one week.

So when you have only a few rehearsals to learn something, perform it, then show up next week and learn and perform an entirely new set of music, sheet music becomes really important, and it’s not feasible to memorize something you’re only going to play for one week.

I’m not saying one is better or worse. It’s just different. Musical acts that play the same music repeatedly can memorize it more easily. If you play new music every week, it’s not practical to memorize.