It's absolutly wonderful that your friend is a great musician, but that is not what being a Drum Major is all about. Think about it; if she is such a great player, she should be a section leader playing her instrument, not leading the whole band. And, yes, drum majors should be great musicians, but they also need experience, and formost power. Which means that the honor of being a leader should go to people that have been in the band the longest, the seniors. I do not know about other bands, but I show my seniors the highest form of respect. I know they know more that me, and they have always been ahead of me to help and to look up to, and have been working for a long time to be where they are. Your friend had no right to disrespect all of those years of hard work those older kids put forth to make it to their spots, and to take away something they worked so hard for. And the whole part about her knowing how to play almost all instruments has little inpact on the situation. You know the saying; jack of all trades, master of none.
It is wrong for the kids to be mean to a person who your BD picked out, and I'm gonna assume he/she is a good one. But he/she should have seen the consequences. The older kids feel snubed for having something taken away, and the younger ones probably feel their seinors deserved it more. Sadly, her lack of experence and the student's attitude twards her will in turn cause a negitive inpact on your season. Without a person to follow and respect, your band has nothing. She is not the only one in the band; there are other's who will never get this experence again that need to be thought about. I sugest that this girl gives the position to a more qualified and powerful seinor, in order to make the seinor's year the best possible and to gain respect and try again when she gets that senority, to become the best Drum Major she can be.