TS1897: If music doesn't play in iTunes for WindowsLearn about If music doesn't play in iTunes for Windows
Currently Being ModeratedNov 13, 2012 6:38 AM (in response to abrame)
Are these tracks you have downloaded from the iTunes Store or were they imported from outside of iTunes? If they are iTunes downloads, delete them from your library and redownload again at no cost via iCloud.
Otherwise, you'll need to re-rip or reimport these music into iTunes from its original source.