That is definitely the dorkiest thing I can possibly think of at the moment. You win!
High school band is competitive in a lot of states. Look at Texas as one of the prime examples. There are region/area competitions along with state championships. South Carolina, FL, Indiana, and several others do this too. There's also a national circuit, BOA (bands of america) which has regionals, super regionals (Atlanta, San Antonio and a few others), and Grand Nationals held at Lucas Oil Stadium in Indianapolis every November. Japan has a highly competitive circuit as well, JMBA. The USA has the "major leagues" of marching each summer, DCI. Brass/percussion/guard only.
One of the lead performers in Cirque du Soleil's "Mystere" is actually one of the most famous marching band composers in the world, and pushed the art further. Writing for 200+ members, including brass, woodwinds, mallet percussion, 3+ synthesizers, drumline percussion and auxiliary percussion is difficult, but can give some amazing results.
Crowds at DCI competitions can get up to around 40,000-50,000 people (half of the stadium is closed off for acoustical reasons). Up to 50,000 people...just there to watch the band (drum corps) perform. No football game.
Excuse me while I nerd out:
The Cavaliers Drum & Bugle Corps, from Rosemont IL. 99.150 out of 100, and a perfect example of the musical + athletic aspect, and how difficult it really is to do this.
[ame=http://www.youtube.com/watch?v=bXa6VAqRlgA]YouTube - Cavaliers 2002 Frameworks[/ame]
2nd place overall nationwide, a high school from San Antonio TX; widely considered to be one of the single best shows of all time (music wise, concept wise, visual wise)
[ame=http://www.youtube.com/watch?v=BOZpITctrc0]YouTube - Ronald Reagan High School Band 2003: Beyond Perimeters[/ame]
And Japan. All competitions in Japan are held indoors, and their season is from Aug-Dec. Some bands are school sponsored, some church, some just community. This wasn't even the winning show of their competition, but it was my favorite:
[ame=http://www.youtube.com/watch?v=ZtmapF4-6m4]YouTube - Selection from Samuel Barber[/ame]
Japanese Church band:
[ame="http://www.youtube.com/watch?v=zZz3rpJZCMM"]YouTube- Aimachi Marching Band 2008 (HQ)[/ame]
And one final one:
[ame="http://www.youtube.com/watch?v=Gp4Uw0EDLl4"]YouTube- Nishihara Marching Band show 2001 national[/ame]