Why can't I sync music from Freedom Call or Amon Amarth to my mobile devices? They work on the pc and I have premium.

While albums I have bought from Amon Amarth such as Surtur Rising seems to work on my Iphone stuff I pay for via spotify doesn't.

"Track not synced, if you own the track, you can sync it from your computer"

This message I get when trying to sync music like "The Wanderer - Freedom Call" or "Where is your god - Amon Amarth" to my phone.

 Or is it some groups just doesnt "release" all ther music you you? All other music I have work fine, both from local and music I made my own playlists from via Spotify radio for example.

Regards

Peter.