Hi ​@jerk - Oh! From a customer support perspective, that sounded entirely wrong! 

Welcome to the Sonos Community!

Sorry to hear of this issue you are having with playing music stored on an external drive.

Happily, I think following the steps outlined on our No tracks from Mac USB drive in Sonos music library will be the solution.

I hope this helps.

I am getting the error message

Sonos was unable to add the music folder

Unable to add the shared folder “/mycomputername/My Music” to you Music Library (913).  

I used the app on the Mac other try and connect the library which is actually at //mycomputername/volumes/Crucial X9 Pro/My Music

Do I have to share every folder inside of my music as well?   For further background, I copied my music that I own from iTunes to this new music folder.

Hi ​@jerk 

Error 913 signifies that the system encountered an unsupported version of SMB on the server (your Mac).

If you are using the Sonos app for macOS to set up the share, be sure to only use the bottom of the 3 options provided when adding a path - to set up a NAS share - even though you are using your Mac as the server.

Please see our guide on setting up a music share:

If the steps there do not resolve the issue, I recommend you get in touch with our technical support team who have tools at their disposal that will allow them to give you advice specific to your Sonos system and what it reports.

I hope this helps.

Hi ​@jerk 

No, just the My Music parent folder.

Sorry ​@jerk 

I misread your question and answered if you needed to add the share of each folder.

You don’t need to share each folder, but I do recommend ensuring in the folder’s properties that the sharing and permissions are applied to all child objects (files and sub-folders).

When you use the MAC Sonos app, it doesn’t give you the option 3 for NAS.  It simply provides a popup to go through a series of prompts to build the complete path name to the folder.

Hi ​@jerk 

After opening the Music Library management page, you will see this window:

After clicking on Add (+ on macOS), you will then see this:

Please only use the third option (Networked device). For it to work, you will first need to set up a network shared folder on your Mac, as described on our Share your macOS music folder with Sonos help page, or the articles linked-to earlier.

I hope this helps.

I’m still getting an error message.  Let me try and upload the screen shots

and then

Finally

Have you tried using forward slashes instead of back slashes? (Could be backslashes instead of forward)

//rkazoomac/volumes/CrucialX9Pro/MyMusic

makes more sense but I get the same error.