No one can claim ownership of a traditional song, or a story, or someone else’s poem. However, there is a kind of optimal etiquette around this, and everything works better when people are respectful of each other’s repertoires.
When you start out as a new performer, the odds are you’ll have no idea what the people around you know, and you may pick up something someone else is performing. However, the probability is that as a new performer, you’ll pick up fairly obvious material (let’s nod to good old John Barleycorn again.) This is ok, and something not to worry about too much. There are things that happen around certain kinds of material, I’ll be back to that in a moment.
However, hearing a piece performed by someone in the same circles as you and thinking ‘I’ll have that’ is not a good way to go. Many songs and stories share content, and having a different version from someone else works well, but taking someone’s version to perform in the same spaces, is bad manners. If you are going places they are not, that can be fine. Otherwise, ask. It may be that this is the sort of beginner’s piece that the performer is happy to let you have, or that they don’t mind sharing it. Get permission.
If the material you want to borrow is the creation of someone in your circle, really, really get permission. Material written by people you don’t know (youtube has become such an interesting part of the oral tradition) is fair game, but do credit it where you can.
When I started singing folk songs in public places, I sang Wild Mountain Thyme, Bonny Ship the Diamond, The Leaving of Liverpool, High Germany, and others. Nobody else at the club I was going to seemed to be singing them. My repertoire expanded rapidly in that first year and became more diverse, less obvious. Then I watched as other new-to-folk people came along, and sang a lot of the things I’d been singing. I put those songs down. It was fine. I’d had my time with them, and other people needed them more than I did. No doubt, other people had stopped singing those songs when I started.
The process of handing material over is part of what helps us all to grow, helps new people get started, helps keep things moving. I started a new singing venture this autumn. One of the regulars has picked up Wild Mountain Thyme. Another expressed enthusiasm when I sang Shenandoah. I sent her the words, happily, and have since heard her sing it. There are balances to find around what we keep and what we let go of, but it’s a key part to participating in a living tradition.