What are the key differences between Chianti and Brunello di Montalcino?

Chianti, a blend of typically up to ten grape varietals grown in Chianti region of Tuscany is a popular complex robust red wine. Brunello di Montalcino, which is sourced from Sangiovese grapes grown in the Montalcino region and is definition of a robust tannin structure, amazing flavor, and amazing aging potential, is a different wine compared to Chianti Classico.