I really wish you could access audio data from across an origin. Preventing that access seems to me like it's mostly just nice for YouTube, Spotify, SoundCloud et al to not have others do things with their audio/video data. Why should my browser care to help them like that?<p>For example, I have built a few music visualizers and have had to run a local youtube-dl server that disables cors, just to be able to visualize music for a youtube video. I just want to draw patterns on my screen while some music plays, I'd even be fine with the ads! But I have to engage in some form of piracy to do this.<p>The music is <i>already playing through my speakers</i>, so I should be able to <i>access that data!</i><p>(edit: I want to clarify: I know that one <i>can</i> set cors options on audio elements to enable cross-origins references, but it requires the <i>server</i> to allow you to -- which is what I'm doing with the youtube-dl server. <i>That</i> is the real problem: CORS is being used by youtube for copyright protection, not for user-safety. <i>I</i> know that accessing a youtube video across origins from a page I <i>wrote myself</i> is safe, but CORS enables youtube to stop me from accessing that data, in the name of safety.)