Maybe you need to install the Windows Media Player plugin (np-mswmp.dll)

• https://support.mozilla.org/kb/Using+the+Windows+Media+Player+plugin+with+Firefox
• http://kb.mozillazine.org/Windows_Media_Player#Missing_plugin

• http://www.interoperabilitybridges.com/windows-media-player-firefox-plugin-download

Thanks cor-el! installing the plug-in did the trick!

oops, spoke too soon. worked on one site but now have run into another one that doesn't work: www.briandoerksen.com . what else could I be missing? ie8 and chrome both play this site.

looks like www.briandoeksen.com may use flash but I know my flash and shockwave plugins are up to date.

Yes, the briandoerksen.com site is using a Flash player, so that should be working for you with the Flash player installed.

Does the Flash player work properly on other sites?

I'm able to watch flash videos on websites ok. dont understand why this wont work.

a mac computer with firefox plays it fine. could you hear the music?

Yes, I can hear the music on the briandoerksen.com site on Linux.

Clear the cache and the cookies from sites that cause problems.

"Clear the Cache":

• Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now"

"Remove Cookies" from sites causing problems:

• Tools > Options > Privacy > Cookies: "Show Cookies"

Start Firefox in Use Troubleshoot Mode in Firefox to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.org/kb/Safe+Mode

Thanks cor-el that did the trick!!!