elmore, I'm a shy singer...strictly shower and car and places where the world at large cannot hear me...though I do it all the time.  The Lovely Wife, the real vocalist in the family, is always very complimentary and encouraging, telling me I have a nice voice.  She heard me whistling a rather complex Miklos Rozsa piece once (I'm a very good whistler...eat your heart out, Muzzy Marcelleno and Elmo Tanner) and said: "Let me hear that again."  After I complied she commented:  "Just as I thought.  You have perfect pitch."  How she knew this, whether it's true or not, and just what perfect pitch is, I have no idea.