Usually the title comes before, or at least during, the painting. This time I’m still searching for the words. Suggestions from friends:
Sounding wooden (Arthur)
Tree’s voice (Elisa)
Is he playing Bach? (as in tree bark! Maria)
Air on a tree string (Mary)
I’d call it Quartet, not because there are 4, but that the painting is quartered. I love it, btw, because it puts me in mind of Rudolf Bikkers.