Just to add a little backstory, here’s a quote from the YouTube poster:
This is from a documentary shown on Channel 4 in the UK called ‘YoungatHeart’; the name of the New England octogenarian chorus line. The performer here is Fred Knittle, who suffers from congestive heart failure. This song was intended to be a duet between Fred and another chorus member, Bob Salvini. Sadly, Bob died of a heart attack and it was left to Fred to carry the song on his own. If I’m correct, the people you see crying at 01:13 are Bob’s family. The lady you occasionally see mouthing the lyrics in the audience is Fred’s wife.