Linux is built on the idea of open source. Even proprietary solutions such as
Realplayer have open source counterparts. In this case it is Helix which if you
go to the Real site is officially sanctioned. In other words, you can probably
get what you want to work without resorting to mental and physical gymnastics.
Helix player is in the repositories.

In addition there are many open source programs dedicated to the purpose that
you want to use Realplayer for. Therefore if you have the libraries or
dependencies to play Realaudio then you can probably use another application to
do just what you want. Check out the repositories and what you want to do and
you will likely find a simpler solution.