Please see later discussion. I wasn't clicking a link. When I do that, the player gets the correct URL for the media and plays normally.

That page doesn't play for me in IE11 or Google Chrome either. It seems there is a bug in the way the player is set up: the file name for the media is incomplete (just .mid without the first part of the name).

By the way, if "Microsoft® Windows Media Player Firefox Plugin 1.0.0.8" does not appear on your Add-ons page --

You can check using either:

• Ctrl+Shift+a
• orange Firefox button (or Tools menu) > Add-ons

In the left column, click Plugins

-- then see this article for where to download and a settings change to make sure Firefox can see it: Play Windows Media files in Firefox with the Windows Media plugin.

What are links to midi files on that page?

I only get mp3 files that play for me with the built-in HTML5 media player on Linux.

• http://www.cyberbass.com/Major_Works/Bach_J_S/Bach_St_Matthew_Passion/B0244_01_s2.mp3

• https://msdn.microsoft.com/en-us/library/windows/desktop/ms696274(v=vs.85).aspx

Hi cor-el, on that particular page, the script opens the player "below the fold" (see attached screen shot) but on some of the others you can choose from the drop-down such as the Christmas oratorio the player is closer to the top. The choice of media could be different based on your OS.

I have attached an image of how I see the page.
All green links open a player in a the tab (best would be a middle-click) and link to mp3 files.

OK, I've changed the UA and now see a not working media player area because the Gecko Media player can't play midi files on Linux.
Once I click a link then the code looks OK.

<embed type="application/x-mplayer2" pluginspage="http://microsoft.com/windows/mediaplayer/en/download/" id="CyberBass" name="mediaPlayer" displaysize="0" autosize="0" bgcolor="darkblue" showcontrols="0" showtracker="0" playcount="100" showdisplay="0" showstatusbar="0" videoborder3d="0" src="Bach_St_Matthew_Passion/b0244_29_s.mid" autostart="1" loop="0" rate="1" balance="0" height="60" width="350">

useragent="Mozilla/5.0 (Windows NT 6.1; rv:26.0) Gecko/20100101 Firefox/26.0";
<pre><nowiki>appname="Netscape";
appversion="5.0 (Windows; en-US)";
platform="Win32";

I've checked the JS file and both Linux and Android get .mp3 files offered.

• http://www.cyberbass.com/Java/CBPlay2.js

Setting general.appversion.override = 5.0 (Android; en-US) or 5.0 (Linux; en-US) seems to be sufficient to get the mp3 links.

I forgot to post my reply?

My mistake was not clicking one of the green links. When I choose any of them, the Windows Media Player plugin is properly directed to the midi media and it plays as expected. My mistake was thinking the music played automatically.