And last year he was 80.
It’s a good chance to point out (again) his fine 2000 interview with the Onion AV Club. Here he is on the topic of satire:
I’m fond of quoting Peter Cook, who talked about the satirical Berlin cabarets of the ’30s, which did so much to stop the rise of Hitler and prevent the Second World War. You think, “Oh, wow! This is great! We need a song like this, and that will really convert people. Then they’ll say, ‘Oh, I thought war was good, but now I realize war is bad.'” No, it’s not going to change much.
More at our Lehrer biography.