Don't ask. I just imagined certain songs with these scenes and thought I'd share them just for them just for the fun of it. It's not a lot, but just thought I'd share. 

OPENING SCENE/RETURNING HOME: Try by Jay Chou & Patrick Brasca

https://youtu.be/TDP5ktmQFto

KNIFE TAG: Till I find you by Austin Mahone

https://youtu.be/HljKLnIRa_U

SLOW DANCE OUTSIDE MR. PING'S: Believe by Mumford and Sons

https://youtu.be/9cpmSfUyHyo

PO LEAVES WITH LI/THE QUIET BEFORE KAI'S ARRIVAL: Cannonball by Kiesza

https://youtu.be/-B9uLGCPuIA

FIGHTING KAI IN THE VALLEY: Lord Shen Epic Theme Ft. Kai by Samuel Kim Music (why is there no epic Tai Lung music, huh?)

https://youtu.be/XZmF30EmY3M

TRACKING PO WITH THE ORB: Beloved by VNV

https://youtu.be/N939-xgTBrM

PO AND TIGRESS' FIRST KISS/ESCAPING THE AVALANCHE: Keep holding on by Avril Lavigne

https://youtu.be/5VRVPHWI9Dc

EPILOGUE/END CREDITS MUSIC: Do or Die by 30 Seconds to Mars

https://youtu.be/o0vb5mGca7o