songs greyed out in itunes

I just bought two albums on my iPod and after syncing with my itunes, the songs show up but are greyed out. I can't play them on my computer and can't figure out what is causing the songs to be greyed out. I clicked the button to "download" the songs after purchasing. They all show up under my "download" folder but they're greyed out there too. I'm not sure what to do. Any help is greatly appreciated!

~ Andy