The 'Send to Client' feature allows you to send this list of tracks to your producer(s) for approval.
He/She will be able to approve or decline a track, then save the changes back to the list..
Once the client saves the changes to the list, you will be notified via email.
You can have more than one client commenting on the same list.
You will see their comments below the list in your current shopping Cart and be able to remove items, add different items or go ahead with your purchase.