Music works, getting bands or musicians because they're famous doesn't work.

Getting Muse or whoever to do a regular gig in your event doesn't set the right tone. League of Legends stuff only works because they hire musicians to write songs specifically for Worlds.

Valve has this whole thing completely figured out imo. Every year at TI they have the same main theme of Dota played in different styles by different artists. One year they had Lindsey Stirling, the year after that it was some Russian guys from Youtube who do acapella covers of video game and film music, last year it was a multinational band performing the songs in an African/middle-eastern style.