LTS: "They learned their tunes by ear"
Not all of them. Like Hardy, many village band musicians left behind manuscript books, and I'm sure those that survive now are a small fraction of what used to exist.

You're right, of course, that they played for all social functions, and as musical talent knows no social barriers they were likely a mixture of people of different classes brought together by a common interest. I'd guess it would be more the middle classes that had the time and could afford instruments or a musical education, though musicians who retired from the army were a source of village band instruments too.

I'd imagine the musical standard varied wildly from village to village too!

Anahata