I attempted to play the audio excerpt in https://en.wikipedia.org/wiki/Psalms_chord on a Windows 7 computer with IE11 and some recent version of Java installed. (If you want to know the precise Java version number, ask me and I'll check for you.)
After clicking the play button, IE froze for a few seconds, then a Java message appeared, notifying me that due to Java's security settings (which I am pretty sure were set to the defaults) the applet could not be loaded. There was no sort of "ignore" or "accept the risk" option; I just had to click "OK" and put up with it.
My guess is that Java now requires all applets to be signed, and ours isn't. This means that Ogg audio appears to be unplayable on IE now, without installing an obscure and impossible-to-find addon.