@Rockhead,
feeling ancient
realized that I've seen Burton in concert in the 1970s, the 1980's, the 1990's, and the 2000's. If I see him this decade, I'll have seen him perform in 5 decades. One of us is 110 years old
http://www.youtube.com/watch?v=VRRmSo7-ITY
I appreciate how he's modified the key he sings in. He knows the strengths and limits of his voice.