Class level Visualization

Hi Everyone,

When I search my KG using Stardog explorer, I'm facing the following challenge, I might be missing something very basic, please let me know.

I created the sample "GettingStarted_Music" database and loaded the data, when I want to search this KG in Stardog explorer I'm not able to visualize as a Class. I'm able to search a particular person but when I visualize as a graph I'm not seeing the person as a class, on the right hand side it is showing as "No Class", any reason why this is happening. Please refer to the following image.