I'm going to differ with Marje somewhat. I think it helps to have and understand one's connection to the lifestyle described in song, whether it's first-hand or a family heritage. That is where the music comes from, after all.

Sailors are better shantiers, and (if I ever get around to learning a decent selection of em) I'm a better performer of "songs of the great north woods" for having been a forest worker.

As for sources, I learned em from old records and sometimes books. Imagine.

Willie-O