I'm not able to add songs to my library all of a sudden and can't figure out why

Hello prmac50, 

We understand that you’re attempting to add music to your library on your iMac. It appears that you’ve reviewed Add and download music from Apple Music to troubleshoot the situation. 

Are you an Apple Music subscriber? What happens when you try to add music to your library? If you are an Apple Music subscriber and use other devices with your subscription, does the issue persist there? 

Thanks.