To view all of the piano's assigned to a client, you can pull up their client record or do a search in the pianos tab.
Viewing Piano List from Client Record
Click the "Client" tab and search for the customer by name or other credentials. Select the record from the search results to pull up the client record.
Scroll down to the "Pianos" box (in between the client information box and timeline). There you will find any pianos assigned to that client
Viewing Piano List from Pianos Tab
You can also do a quick search for client pianos from the Pianos tab. Click the "Piano" tab and search for the customer by name or other credentials. Any pianos assigned to that client will show in the search results