From the WGI web site:
WGI Sport of the Arts is the world's premier organization producing indoor color guard, percussion, and wind ensemble competitions. As a non-profit youth organization, WGI serves as the leading governing body of the indoor winter guard, percussion and winds activities. It is called the Sport of the Arts because it brings music to life through performance in a competitive format. Now entering its 39th year in 2016, the sport continues to evolve and grow. There were more than 36,000 participants at the regional level, and more than 12,000 participants at the Sport of the Arts World Championships this past April.