How to find which Control-Command keys are mapped to particular programs

Almost all of the keyboard shortcuts you've learned on Windows are the same on the Mac. The difference is which modifier key you use to invoke them.

On Windows, shortcuts are typically invoked with the Ctrl modifier key.

On the Mac, you use the key, also known as the "command" key. It's in the same physical position as the Alt key on a Windows keyboard, but is nothing like the Alt key.

The Mac has its own Alt key, labeled Opt/Alt. Its primary use is a secondary modifier for keystrokes. Command-Option-S might be "Save As", for example, while Command-S is regular "Save".

The Ctrl key is there on a Mac keyboard, too, but it's hardly ever used for anything.

The relative layouts look something like this:

     PC:     Ctrl Windows Alt

     Mac:   Ctrl Opt/Alt

The problem is that you're most likely using a PC keyboard on your Mac. In that specific case, the Opt/Alt and keys are reversed. You can change this in System Preferences, under Keyboard. Truly a huge pain in the rear for switchers. That layout looks like this, instead:

     PC keyboard on Mac:   Ctrl Opt/Alt

Apple's website has some pretty good hints and tips for Windows switchers. Start here for answers to your specific question about keyboard shortcuts. Then go here and read everything!

The beeping you are hearing in this context is not because those key commands are mapped to something but quite the contrary because they are not.

Typing an unmapped key command will result in an audible bell.

As you note Command-Control-Right in results in an audible bell in Mail.app. You will also note that Command-N results in a new message.

So here's a proof to confirm my assertion:

• Open System Preferences > Keyboard
• Select Keyboard Shortcuts from the pillbox at the top
• From the menu at the right choose Application Shortcuts
• Click the small + sign at the bottom left of the right panel
• From the Application pull down select Mail
• In the Menu Title field type "New Message" (no quotes)
• Place your cursor in the Keyboard Shortcut field and type Command-Control-Right
• Click Add

Now return to Mail and type Command-Control-Right. A new message will be created but if you type Command-N you will hear the audible bell. This is because Command-N is no longer mapped to anything. We replaced it.

So when you hear the audible bell it often means that you are trying to do something that is not possible (i.e. typing a key command that has no meaning for the current application).