A choir turns separate lungs into something nobody can produce alone.

Some things exist only in the plural. No single voice in a choir is producing the sound the room hears, and no amount of individual excellence would get you there, because the effect comes from the blending rather than from anyone’s contribution. Joining that means giving up being distinguishable, which is a real cost and also the entire mechanism.

If you are part of something collective, judge it by what the group produces rather than by how audible you were in it. And if you have avoided joining things because your part would be small, that is exactly the sort of smallness that adds up.