"My Music" on iPhone its empty at online mode

[Allyouneed]

Hello,

since this morning I have the problem that on my iPhone all songs, album and artist are empty at the online mode. On my PC I can see all. The conecting between both ist posssible and I can operate the PC with the iPhone. Why I can't see anywthing on the iPhone?

Thanks for help!

PS: Sorry for the bad English

[Allyouneed]

Supplement:

I have a premium account and the songs are usually stored at the offline mode.