I was watching the Arena documentary recently, and it prompted me to think about the quality of Sinatra's voice, perhaps, more accurately, his ability to deliver a lyric which sucked you into the song he was singing. He was an influence on me from my childhood, but I really came to appreciate him most as I grew older.
Was he the world's greatest singer? In the 20th century, I think the answer is yes. (Though it would be hard to compare him with Pavarotti, say, who had more power and a purer quality, but who sang notes, not words.)
What do you think?