Funny how your subconcious self is always at work.
I had this song on my mind all morning. Just the song. Not the lyrics. I sort of thought it might be by Elvis Costello, but wasn't sure.
Finally, I called an old friend and sang the first few lines for him. Of course he knew it. "It's 'She', by Elvis Costello and Burt Bacharach".
I went and Googled the lyrics. This is how it begins:
May be the face I can't forget
A trace of pleasure or regret
May be my treasure or the price I have to pay
She may be the song that summer sings
May be the chill that autumn brings
May be a hundred different things
Within the measure of a day.