need mailcap entry for mp3

[William Kreuter]

Can someone state the .mailcap and .mime.types entries that will get
Netscape Communicator 4.75 to drop an mp3 into RealPlayer 7?  I've
tried a few combinations, including just adding "mp3" to "ra,ram" in
the existing entries which work fine for Realaudio streams.  The
following don't work either.

..mailcap:
audio/x-mp3;realplay %s
or
application/mp3;realplay %s

..mime.types:
type=audio/x-mp3 exts="mp3"
or
type=application/mp3 exts="mp3"

Billy