Loved this interview with Marianne Vos in BICYCLING magazine.
"B: Do you like to train with music?
MV: I don't like it too much. You're not really into the normal sound of riding your bike and the birds and the trees and the wind. You should listen to that sometimes, too.
I sing in the bunch. I can imagine that's pretty annoying. The other riders don't like it. I pass other riders or a teammate, and it's like, It can only be you. Always singing on the climb. Please do it on the descent, and not on the climb."