About iCloud Music Library icons and status - Apple Support
- Ineligible: Your computer isn't authorized to play this song or the file type can't be added to iCloud Music Library. A song might be ineligible if it wasn't purchased from the iTunes Store or was purchased using a different Apple ID, or if the song file is larger than 200 MB, is longer than two hours, or was encoded at 96 Kbps or less.
- Waiting: This song is in the process of being matched and hasn't been processed or is waiting to be uploaded to iCloud Music Library.
Whether a song is 'ineligible' or 'waiting' you should still be able to play it in iTunes. Unless you're getting a specific error message, if you're unable to play specific songs, there are a few things you can check out in the section titled 'If you're missing or can't play music' from this article
Access your music collection on all of your devices with Apple Music - Apple Support