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
KNIFE TAG: Till I find you by Austin Mahone
SLOW DANCE OUTSIDE MR. PING'S: Believe by Mumford and Sons
PO LEAVES WITH LI/THE QUIET BEFORE KAI'S ARRIVAL: Cannonball by Kiesza
FIGHTING KAI IN THE VALLEY: Lord Shen Epic Theme Ft. Kai by Samuel Kim Music (why is there no epic Tai Lung music, huh?)
TRACKING PO WITH THE ORB: Beloved by VNV
PO AND TIGRESS' FIRST KISS/ESCAPING THE AVALANCHE: Keep holding on by Avril Lavigne
EPILOGUE/END CREDITS MUSIC: Do or Die by 30 Seconds to Mars