I'm looking for a way to add 3 level product catalog to cart based on MVC musicstore sample:
root product categories
sub categories
products
Clicking in catalog item should show subitems with pictures.
Control is placed to Site.Master. It can be treeview in cart left side or horizontal menu in upper part of screen.
Data is read from database from controller.
How to implement this ? Which free control is best for this or is there sample code for this ?

no response yet

Probably because your question is not clear.