True streaming requires the use of special streaming server, unfortunately this can lead to high cost and high levels of administration.  Luckily, it is possible to do what is known as "psuedo" or HTTP streaming of RealMedia (RealAudo & RealVideo) content.

The first step is to convert your existing audio or video to the RealMedia format.  You can do this with a free tool from RealNetworks website:

http://forms.real.com/rnforms/products/tools/producerbasic/index.html

Second, you will need to create a ".ram" file.  The file should have the extension ".ram" (example: my_new_song.ram) and should be created using a simple text editor (ie, Notepad).  This file is used by RealPlayer to load the RealMedia content.  The contents of the ".ram" file are very simple:

Of course, you will want to replace the "yourdomain.com" with your actual domain name.  Also replace "realmediafile.rm" with the actual name of your real media file.

Third, you will want to upload both the ".rm" and the ".ram" files to your website.

Lastly, you will want to create a link on your webpage to the ".ram" file so that your visitors can click on the link to play to the media.  You may also want to consider providing a link to RealNetworks page where they can download RealPlayer.