Okay so anyone whose ever been in orchestra knows what Shït is about to go down.
To you who don't play an instrument or are not associated with an orchestra, basically tea is spilled evERyWhere. Now, before your Oc or character tries to pick up an instrument (depending on what scenario you should know that there is a certain layout to an orchestra or band. Typically strings are at the front, then the brass and wind at at the very back is percussion- typically.
So a bit like these

It can really work anyway.
I'm gonna take a stab that some may go for violins. Be wary tho, there is firsts and seconds. A bit like in choir, the firsts sing the main tune the majority while seconds are back up. However without second violins, it wouldn't give a good impact to the audience. Everyone in an orchestra is important. If you have any more Questions just ask!

Scenario 1
You were just beginning in orchestra. It was your first day and shyly, you walked up to the conductor. He seemed warm and friendly, gently trying to assure you everything was okay and they were just about to start. He informs you to find a free seat somewhere among your section of the orchestra. Unfortunately there is only one seat left, beside a skeleton that didn't seemed to be more concerned about whoever he was texting rather than playing.

Scenario 2
You had been working your way to the top of your section for years, hoping to finally be recognised. Then who comes walking in but a newbie. At first you thought he was cute. That was until the conductor placed him at the front of the orchestra and even offered him a solo. Slowly you began to grow jealous until one day you call him out...

Scenario 3:
Same as 2 but reversed

Scenario 4:
Make it up!

Here's some memes ;3