- What I desire to know is the format of the music being imported / loaded (wav, mp3, mp4, avi or etc.) At the link below, I find it that all formats aren't supported so to be sure check to see if the music format(s) is supported.
http://support.apple.com/kb/HT3775
- Now, if your music is not in a supported format according to the link above, what you should do is import the media in another format, and the link below should assist on one of the ways to saving a song in itunes in a different format.
http://support.apple.com/kb/PH12367
- Another cause could be that if the music already exist in the library and is in fact an exact duplicate from the exact folder in which it was imported in from, the library will fail to import it again. Assumably, this isn't your situation, because if it is, that will only mean your media is already imported but displaying itself as unknown. If you come to find out that this is the case be sure to follow the link below to properly edit your media.
http://support.apple.com/kb/PH12360
~ Rashee