When you play Full "Pentakill" Team, their Music should play
Just like with Dj 
When you have a Team of
you should get the Possibility to enable (and disable) their music, since they even have a own album (Smite and Ignite incase you dont know).
Its up to Riot if its already okay just to have these 5 or need the fitting Pentakill Skins, both is fine and would be epic.
Metal