A group of very dedicated people who work tirelessly to help assist high school marching bands. These are usually parents of current or sometimes former band members, and they will often assist in all kinds of band-related activities, from helping with band camps to loading instruments on busses and selling concessions. They can also be found involved in fundraisers and trying to make sure their kid actually sells some band candy this year. Also sometimes known as band boosters, these individuals are often instrumental (no pun intended) to keeping a high school band on its feet.
The band parents helped unload the instrument bus, then they made sure all the band uniforms had been put back correctly. Finally, at 11:30 at night, they went home.