Audirvana will not recognize new HD music file - need some help

I am a fool when it comes to Audirvana.  I had an external HD synched to my iMac playing through Audirvana, but I just recently put all my Hi-Rez files on a new HD and Audirvana will not recognize those files, it only shows the files on the old HD, which is disconnected.  I have spent a few hours trying to figure out with no success.  The new files are in FLAC format.  Any help would be appreciated.  Thank you. 
You have to add the HD and location of the file to your Audirvana library. Go to preferences in the app. The library options are in there somewhere.
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Yep, I did that but it still won't play.  It seems to balk when I try to sync it to the new location. 
See if the old drive is still on the computer. Delete it in system settings and reboot. Then synch.
The meta art from the old HD is still appearing when I start Audirvana and surprisingly some of it plays event tho the source (i.e., HD) as been disconnected.  I don't understand how to delete it.