MacOS – How to do to stop the Play / Pause button from opening iTunes

It appears the implementation of play/pause may be bugged - or simply changed in iTunes 10 / IntelliType 8.0. I downloaded and installed the following:

http://maximized.com/freeware/scriptsforitunes/default.asp

It is a series of VBS scripts that are run with iTunes. I make no warrantee or guarantee as to their safety. Firstly, I removed mmKeys.dll, and then edited PlayPause.vbs. For case 0 and 1, instead of running iTunes.PlayPause, it works if I use iTunes.Play and iTunes.Pause respectively. I then mapped this VBS file to my play pause button. And bam! It works!

' Do the appropriate thing
select case CurState
    case 0
        ' Stopped
        iTunes.Play
    case 1
        ' Playing
        iTunes.Pause
    case 2
        ' Fast-forwarding
        iTunes.Resume
    case 3
        ' Rewinding
        iTunes.Resume
end select

I know this question is old, but other answers don't really solve the problem.

All you have to do is to install Karabiner (previously known as KeyRemap4MacBook).

Then you just have to add the wanted behavior.

• Open Preferences menu.
• Switch to Misc & Uninstall tab
• Click on Open private.xml
• Open the file private.xml in your favorite Text Editor

• Replace the empty file by this definition :

  <?xml version="1.0"?>
  <root>
      <!-- Spotify Path -->
      <vkopenurldef>
          <name>KeyCode::VK_OPEN_URL_APP_Spotify</name>
          <url type="file">/Applications/Spotify.app</url>
      </vkopenurldef>
  
      <!-- Set Spotify definition -->
      <appdef>
          <appname>SPOTIFY</appname>
          <equal>com.spotify.client</equal>
      </appdef>
  
      <!-- Use 'Music Play' key to launch Spotify if not ever in the application -->
      <!-- else, act as normal play/pause button in Spotify, Itunes -->
      <item>
          <name>Change Play key to launch Spotify</name>
          <identifier>private.play_launch_spotify</identifier>
          <not>SPOTIFY, ITUNES</not>
          <autogen>
              __KeyToKey__,
              ConsumerKeyCode::MUSIC_PLAY,
              KeyCode::VK_OPEN_URL_APP_Spotify,
          </autogen>
      </item>
  </root>
  

• Go back to Change Key tab and click on Reload XML button.

• You now just have to enable the new item added at the top of the list: