For those who do Battle Spot, here's all the confirmed options for the battle spot:
>Music 1: Trainer
>Music 2: Wild Pokemon
>Music 3: Rival
>Music 4: Gym Leader
>Music 5: Magma/Aqua Grunt
>Music 6: Magma/Aqua Boss
>Music 7: Primal Groudon/Primal Kyogre
>Music 8: Elite 4
>Music 9: Champion
>Music 14: Uxie/Mesprit/Azelf

I haven't gotten around to catching every single legendary, so I'll assume that 9-13 are also legendary related themes, as well as a couple after 14. I'm not sure where Zinnia's and Wally's themes are but I think they should be in there somewhere.