Have you enjoyed the deliciously deep voice that sang “You’re a Mean One, Mr. Grinch”? I began to wonder just who that singer was. It turns out to be the same man who, for over five decades, was the “Grrreat!” voice of Tony the Tiger! The equally colorful name of this singer is Thurl Ravenscroft (1914–2005), and his many roles included the voiceover for the character Stewpot in “South Pacific.” That’s the sailor who works his way down to that incredibly low note on the line “There is absolutely nothing like the frame of a dame.” I don’t know anyone who isn’t fascinated when a true bass singer descends the scale to the bottom of his range. We can’t wait to hear just how low he will finally go, until he satisfyingly arrives at a pitch even lower than we imagined. Singing groups such as barbershop quartets, gospel quartets, and …