What do you do when the music stops?

I was in the cath lab at 3 a.m., just after a stent went in, and the surgeon turned off the beeping. The room went quiet except for the hum of the monitors. Then, out of nowhere, I started humming this old song—something I haven’t thought about in years. It wasn’t even mine. I don’t know why it came back. Now I keep wondering: what if we’re all waiting for a tune that never comes? What do you do when the music stops?