Certain websites have a rights management department for works in copyright. With video, Youtube is famous for the ads it sells and the forwarding of some revenue to copyright owners that protest.
Without video, I believe soundcloud does this, but it is not so famous. But it does carry works played by individuals written by many pop bands, which are certainly in copyright. If the owner protests, the website can certainly delete your post if the arrangement is not satisfactory. There are conditions where works of dead composers are still in copyright, so investigate that if recording another work where that might apply.
If you make a recording of an arrangement by someone living or otherwise in copyright, be sure to credit the arranger with correct spelling, and use a website with a rights management department. I wouldn't post something in copyright on a low cost low service website like pianostreet.