Drumroll editor looks nice, but how does it work?

I am learning how to make drum and percussion sounds and successfully added many sounds with the drumset editor. Now I have discovered the drumroll editor, but it does not do anything after I open it up.

Can someone provide instructions? Can I make edits inside drumroll editor, or at least watch as each note sounds while playing? Maybe there is a bug in my usage?
Anyway, it looks very helpful, but not doing anything for me.

Any tips or hints or direction to instructions would be helpful.