Just so you know Drum and Bugle Corps is not an activity set up by age (high school, college). There are three divisions (1,2,3) ranked by size and many other variables, 1 being the largest and usually the highest quality and anyone from 14 through 21 can go and try to audition for any of the corps out there. Bear in mind that the top corps in the country are more than a little hard to make. Check out
Drum Corps International (DCI) -- Marching Music's Major League - 35 to find out more about it. I marched 3 years with the Blue Stars Drum and Bugle Corps so I consider myself competent to mention that I think some of your info on the subject is a little off. I don't mean to be condiscending or anything, but check out the site to learn more about it...
Thanks,
Matt
p.s. WELCOME to TM. This site is a wealth of information and a great place for trumpet students like us to learn and grow.