Well, if you have some player that is associated with mp3 files, then you
can just launch that file.
So,
application.FollowHyperlink "c:\my documents\test.doc"
The above would launch a word doc (just as if your clicked on it).
application.FollowHyperlink "c:\my documents\test.xls"
The above would launch a Excel Doc (just as if you clicked on it).
So,
application.FollowHyperlink "c:\my documents\test.mp3"
All of the above assumes that you have some mp3 player installed. I am sure
for your Karaoke idea, you will run a rather nice player, since you want
thinks like tempo, and pitch controls. So, it would probably be best to get
a real good mp3 player, and install it separate from ms-access.
However, as above, you can certainly launch the songs easily.