Can't Sync Local Files

[carolinelisabet]

I've seen a lot of threads about this, but I can't seem to get anything to work.

I have an iPhone 4S and a MacBook Pro with Spotify Premium. I have many files that I have transferred from iTunes (originally from CDs or bought on iTunes) and no matter what I do they just will not sync to play on my phone. I have synced over the same wireless network many times and I have both playlists set to work offline. I've restarted and deleted and etc. and nothing works! It's really frustrating paying $10 a month when you can't even play all your music. The files show as grey on my phone and when I click on them it tells me to sync...which I've done.

Hopefully I'm just missing something really simple. Thanks!