OK, I realize this is going to require some explaining so bear with me for a while.
On OS X all application menus live in the menubar. It's the thin bar along the top of the screen in all those OS X screenshots you see. All applications also have what is referred to as the "Application menu" and then the actual menu entries for the application.
The "Application menu" gets it's name from the name of the app it is displaying. In the case of Amarok this results in duplicate menu items named "Amarok".

Amarok   Amarok    Playlist   Mode   Tools   Settings   Help

is the resulting menu setup. Quite confusing. To rectify this I've renamed the second Amarok entry Playback, as it refers to entries that have to do with playback. This gives us

Amarok   Playback    Playlist   Mode   Tools   Settings   Help

The Mode menu entry only has two items, and honestly doesn't really make much sense all by itself (Mode of what?) so I removed the playback mode entries, and put them in the Playback menu. The result is now

Amarok   Playback    Playlist   Tools   Settings   Help

The Application menu (labelled Amarok by the OS) also has some standard entries. One of these standard entries is the Preferences. Qt, through some string replacement black magic  takes Settings -> Configure Amarok... and converts it to Amarok -> Preferences. This does two things. First it puts the entry in a location where OS X users expect there application preferences to be, second it gives it a shortcut that OS X users know will automatically take them to the applications preferences.
It also inadvertently leaves only one entry remaining in the Settings menu. I've tried to play around with the code and put it somewhere in the Amarok menu, but I can't find a way to control where it appears.  I also see in the code that there might possibly be other entries that should be in the Settings menu, so I just left it alone. So I went from

Amarok   Playback    Playlist   Tools   Help

which you'll see in the screenshots back to

Amarok   Playback    Playlist   Tools   Settings   Help

The one things that is left outstanding is whether or not to include a "Window" menu entry. This is required by Apple HIG and contains required entries such as Minimize, Zoom (basically Maximize) and allows access to other window which may be opened up by the application.  The problem with this is that those entries in Amarok already have a menu. It's called Tools.
Personally I'm ambivalent on the following of the HIG. But if we want to properly integrate into OS X, i think it's something we should do.

These images show how Amarok would look if I got rid of the Settings menu and put the remaining entry into the Amarok menu. Bad Idea methinks.
http://illogic-al.org/images/screenshots/Picture%203.png

This one shows the proposed contents of the Playback menu  (bye bye "Mode")
http://illogic-al.org/images/screenshots/Picture%204.png

These show the remaining menus
Playlist:    http://illogic-al.org/images/screenshots/Picture%205.png
Tools:    http://illogic-al.org/images/screenshots/Picture%206.png
Help:   http://illogic-al.org/images/screenshots/Picture%207.png


My question to you is: Are the proposed changes acceptable?
Those changes being:
Leaving the Settings menu with (currently) one entry
Renaming the Amarok menu entry to Playback.
Adding the entries from the Mode menu to the Playback menu.

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