Re: members only pages.
If you want them to pay to get to that member page, try the s2member plugin. If you want them just to register (for free), then I think this is the thread with a bunch of possible solutions: https://buddypress.org/community/groups/how-to-and-troubleshooting/forum/topic/how-to-make-a-private-community/
As far as the MP3 player, I don’t know, but I’m sure there are a ton of options. In this case, it wouldn’t need to be BuddyPress specific at all. Just search for an MP3 player that works with a webpage and it can be added to the WordPress page. There might even be a WordPress plugin that does this already.
