Having trouble syncing certain music on iTunes

I'm having trouble syncing only certain music to my phone from my iTunes library. I had downloaded some music from the cloud that I share with my family, and when I either try to play it on my iTunes or download it to my phone, my computer says that it is unauthorized to play that music. So when I hit the button to "authorize my computer", a message then pops up telling me my computer is already authorized. So I'm very confused and frustrated because I have the music in my library, but I am unable to play it on my computer or sync it to my phone. I have tried re-authorizing it many times, but I can't seem to find a solution. If anyone has any input as to what I should do, I would greatly appreciate it! Thank you!