I'm sitting at the FSGW Forebitter/Sea Ballad workshop, John Roberts just defined a Forebitter as a recreational song, sung by sailors in their off hours. They'd have a song circle and sing around. If someone had a request they would toss 50 cents into a hat in the center of the circle. 50 cents = four bits. He had the room going for a while, but he eventually broke into a chuckle. It sounds plausible!