Written and originally recorded by Badfinger (1970).
Hit versions by Nilsson (US#1/UK #1 1971) and Mariah Carey (US #3/UK #1 1994).
From the wiki: “Paul McCartney once described this ballad as ‘…the killer song of all time.’
“At the time of writing the members of Badfinger shared residence in Golders Green, London. One evening, in the midst of the parties, songwriting, touring, in Golders Green, Pete Ham and his girlfriend were about to go out for the evening. But, just as they were leaving, Tom Evans said he had an idea for a song – Ham said, ‘Not tonight, I’ve promised Bev.’ But she thought he would be wondering if he had done the right thing later, if he went out, – she told him – ‘Go into the studio, I’m fine about it..’ He said, ‘Your mouth is smiling, but your eyes are sad.’