You do not mount an audio CD - it does not have a file system.
Some audio CDs also have a data section - they are mounted iso9660.
It is pretty unusual to find cdrom0 in /mnt, it is normally in /media.
However - things can get quite cool with the abstraction layers...
When I load an audio CD, I get a CD icon on my desktop. I can rt-click this icon and select "browse folder", which opens the filebrowser to a location called cdda://sr0 full of files called track*.wav
This has been pseudo-mounted through fuse by the gnome virtual file system.
This is controlled by gvfs-mount, the mountpoints are created in ~/.gvfs
$ ls ~/.gvfs
cdda mount on sr0
That's only one mount-point.
to see the options and short usage.
There is a good discussion
on accessing gvfs mounts using gvfs-mount, and mount.
Naturally, searching LQ