How Do You “Own” A Performance?

“Time was when the ‘authorship’ of a work of art was usually (if not always) a clear-cut matter. Nobody wonders who wrote ‘David Copperfield’ or painted ‘Guernica.’ Even in the performing arts, it’s long been taken for granted that the mere act of performance creates no enforceable property right on the part of the performer… Here’s the problem: Where do you draw the line separating creative performance from actual authorship?”