no new music will sync since ios8.4 update

I've downloaded some new music, added it to itunes, but it won't sync.

I have my iphone set to sync all music.

Interestingly, when I click on music (in the 'on my device' bit), the album is there, but greyed out, and with a strange dotted circle next to each track.

This is all since updating to ios8.4 and itunes12.2

Thanks in advance

Dan