Gives him purpose in his life he was missing before.
Your mountain climber could use music in his life. And yes, making music helps us old folks stay relevant.
I "played" the violin in elementary and high school, disinterestedly, but well-trained. I was a intermediate klezmer fiddle player in NYC, but stopped playing anything at all for 25 years. Now that I have moved back to my home town, I'm taking lessons with a person who learned from my teacher before me. She's 85! I wanted to just learn how to play some country fiddlin', but she's got me playing classical too. Both pose huge challenges for me.