I was in marching band in high school and we were the only band in our conference that did not do competitions. Never noticed bands completely leaving. I can tell you we were there as a feature supporting the football team, and we were fine with that.

All those competition bands are BORING. They play songs no one knows and make amoebic nonsensical formations. Give me a band that makes cool shapes and plays rock and roll any day.

From my experience in following and attending HS football in NE Ohio over the years, the only ones leaving after halftime are the band parents. Bands generally are clogging the concessions areas in 3rd qtr and back in the stands in the 4th.

High School football is like a religion in Ohio. I've seen worshipers leave mid-sermon, but never the Organ-player.

Maybe it’s a function of locality, but my wife and I were band parents (at Charles F. Brush, Brucecuth!) and for the most part, us band parents that did go to the game stayed throughout the game and afterwards. Perhaps it was because the band always played for a bit after the game, like the fight song, etc.), so we wanted to see our kids perform.

I noticed last year that our high school band, which competes on Saturdays and some Sundays, was little involved in the game after halftime. The drumline would have battles with the other school's drumline but generally the band would not play during timeouts or between plays (as they did in the first half) until sometime in the 4th quarter. I can see them focusing on their competition performance because they have more competitions than football games -- some weekends they do two or three competitions -- and get more prestige from doing well at competitions. But I'd also like to see them support the team more after halftime.