Just remembered this duo. I haven't had the good fortune to run into them. They do these short performances on hikes all over my Cascade Mountains. Usually first or last light, so the mountain air can be quite chilly. I've read or heard that it can be challenging tuning their instruments. And overcoming numbed fingers.
Starting at about :37 seconds, the 4 peaks directly behind them are Del Campo, Morningstar, Vesper and Sperry. I've climbed all of those in addition to Dickerman. Just a little idea of what's in my back yard. Not too bad.