Q: i purchase 'harp attack album, but each track is not complete. what do i do?

Other people have been having similar problems with songs over the last few days, I assume that there has been a problem with Apple's servers.

Depending upon what country that you are in (music can't be re-downloaded in all countries) then try deleting the incomplete tracks from your iTunes library and redownload them via the Purchased link under Quick Links on the right-hand side of the iTunes store home page on your computer's iTunes : re-downloading.

If you aren't in a country where you can re-download music or if they re-downloads in the same state then try the 'report a problem' link from your purchase history : log into your account on your computer's iTunes via Store > View My Account and you should then see a Purchase History section with a 'see all' link to the right of it ; click on that and you should see a list of your purchases ; find that album and use the 'Report a Problem' link.