The usual but "non-validating" method is to use both <object> and <embed> tags. If the targetted player is the Windows Media Player, then the object tag needs to contain the appropriate classID for the player, and of course these IDs change as newer versions are released. A Javascript detection script could be used to add the appropriate code, but I notice you're not too keen on adding additional Javascript.
You might consider offering links for each type of media player.. again, a logistical nightmare if you're dealing with over 400 pages!
All in all, I'm in agreement with
speed, using Flash may be the best solution. With around 98% of the Internet enabled desktops having the Flash plugin, you stand a pretty good chance of your audio being heard! :o)
Hope that helps!
Paul
PS. A related link to one of speed's suggestions
To embed, or not to embed