1. Music file format is not supported: iTunes only supports music files in MP3, AAC, AIFF, WAV and Apple Loss formats. If your music file format does not meet the requirements, you can't import it into iTunes.
2. Music file already exists: If your music file already exists in iTunes, importing the same song again will lead to the situation that it cannot be added.
3. Music files are protected by copyright: Some music files may be protected by copyright, and you cannot import them into iTunes without the corresponding authorization.
For the above situation, you can try the following solutions:
1. Convert the music file format: If your music file format does not meet the requirements of iTunes, you can use the audio conversion tool to convert it into a supported format.
2. Delete the existing music file: If your music file already exists in iTunes, you can try to delete it and import it again.
3. purchase authorization: if you need to import copyrighted music files, you can purchase the corresponding authorization to legally import these music files into iTunes.
in a word, if music cannot be added, it may be because the music file format is not supported, the music file already exists or is protected by copyright, etc., and corresponding solutions need to be tried according to the specific situation.