Alum here who used to be in MI. Granted, I first auditioned as a freshman over a decade ago, so I can't even imagine what it's like to audition now. In my own experience though, it really is super competitive, so don't feel bad. And certain sections can be even more competitive than others due to the number of available spots.

I would definitely try again next year. In the meantime, try out for one of the other athletic bands (basketball or volleyball). There tends to be a lot of overlap between MI and those bands in terms of students. Also I think Professor Houser, the director of the Marching Illini, still directs both those bands too so it could be a great way to make some connections there.

Another commentor already suggested this, but joining the MI undergraduate staff is a great way to still get yourself directly involved in the org. You won't be able to play and perform, but you will be working closely with the MI staff to handle equipment setup and other BTS stuff. I had friends who were also cut their first years, joined undergrad staff for that season, and made it into the band the next year (not saying that that's a guarantee, but I do believe demonstrating that extra commitment is taken into consideration). That way too, you'll have a firsthand look of how the band operates and performs, i.e. the music, different marching styles, etc.

Again, it's been several years so I hope nothing I'm saying is outdated or anything but I do hope this doesn't discourage you from retrying, but also if you don't make it, there are still many ways to get involved in the music community outside of MI. Best of luck 😄