The song isn't from any stage show. It was written by Newley for the American Comedy Awards in 1978, a deeply bittersweet song called, "The Man Who Makes You Laugh." I've seen a video of that performance -- it's the best I've seen, and especially poignant in front of that audience of comedians, who gave it an explosive response -- but alas haven't been able to track it down. I've found two others, both very good though. One is on stage in a big nightclub setting, and it's wonderful for that. But I've chosen this smaller version instead.
[Note: an earlier version of this article incorrectly said that Newley wrote it with his longtime collaborator Leslie Bricusse.]
It comes from an appearance on London television, The Michael Parkinson Show. The stage arena is much smaller, but he makes the performance much more personal, and it's riveting. More than a pop number, this is more telling a life story in song -- and performance. Sort of a 5-minute mini-musical. It takes a Newley theme of The Clown and adds some lovely, wistful layers.
Worth noting, at the start of the interview you'll see two other guests. Petula Clark will be recognizable, but the man to Newley's left in glasses is the aforementioned Leslie Bricusse.