I wrestled with it for a couple of hours last night, no real success. Films/Video played from iTunes blanked my Macs screen whenever sync enabled unless I Airplayed to ATV. I gave up trying syncing music as it kept insisting I enable Audio input under "Security & Privacy > General"
There is no audio or Hue Sync settings under that heading the only setting is "Security & Privacy > Privacy" which is enabled for Hue Sync.
I just got done playing with it. It took a little while to get it to work. At first I would click on the button to start the sync and nothing would happen. I restarted the app then started playing music from iTunes and then started the light sync last and it worked. It really worked well, looked awesome in sync with Thunderstruck.
I am not running any beta software though so I dont know if that is playing a role in your issue.