* To install or reinstall Audacity, drag the "Audacity.app" icon in the
   DMG window to the /Applications folder icon on the right. Alternatively,
   drag the "Audacity.app" icon to any other location of your choosing. 

* Do not double-click the "Audacity" icon in the DMG then launch Audacity 
   from there. 

* If you are a first-time user of Audacity, security settings on 
   OS X 10.7 or later may block Audacity being launched. To permanently
   enable Audacity launch, right-click or control-click on the Audacity 
   application in Finder, choose "Open", then in the dialog box that 
   appears, choose "Open".