Jack Li Vigni on Lauri Volpi and the light middle voice - Cotogni's dogma

Part of a discussion by Voice Teacher Jack Li Vigni (Tenor, Voice Teacher Royal Opera House Covent Garden, Curtis Institute of Music, Brooklyn College, Director of Mediterranean Opera Studio and Festival) on the importance of learning the delicate timbre.
This is a selection of Giacomo Lauri Volpi discussing his memories of studying with voice teacher Antonio (Toto) Cotogni and the concept of maintaining the middle voice light (Cotogni Dogma - non ingrossare i centri).