Authenticity is a problematic concept when it comes to all art. In the world of classical music, the problem is especially important to address because most of what we do as musicians is reproduce the music of others. We don't typically own, at least in a strictly philosophical sense, intellectual property over our performances, since they're written by someone else. Unfortunately, as the classical music scene struggles with evolving standards of intellectual property involving the internet and duplication, it simultaneously struggles to evolve out of an antiquated and damaging mindset involving all that music in the public domain!
It's one of those things that, if you operate outside the world of classical musical performance, you'll probably say either "huh?" or "who cares?!", and maybe you're not totally wrong. But maybe you would care more if the world of classical music performance weren't so bogged down in its silly performance practices!
Before writing anything more witty about it, I feel I have to lay down the groundwork for what I want to say.