Aldo Protti was an Italian baritone opera singer, particularly associated with the Italian repertory. He was particularly appreciated in Verdi roles, especially Rigoletto, his greatest role, but also as Alfio, Tonio, Gérard, Scarpia, etc.
From Wikipedia (https://en.wikipedia.org/wiki/Aldo_Protti) under Creative Commons Attribution CC-BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0/legalcode)