You're trying to play RAM files, I see. Thought you were trying to play rpm files. That would be silly.
You're getting those conflict errors because you already have xmms installed.
The files you're trying to play (the ram ones) are Real Audio (yuck!) files. You need to download the Real Audio player. Go to http://www.real.com
and click on the link at the bottom for the UNIX/Linux player.
There is no official support from the "Real" corporation (or whatever the hell they're called) for the Linux version of the RealPlayer. I have it. I use it. It sucks. Lots of obscure error messages. Crappy quality. Doesn't let you record streams. Consider yourself warned.