Should I be offended by a teacher's unnecessary remarks to me?

Hello, there is a school talent show coming up very soon and I had tryouts today. I performed a song with a couple friends of mine and my brother (who wrote the song). The chorus teacher was the judge of the entire ordeal and when we finished playing our song and prior to it she made a few very rude and offensive remarks to us regarding how she had students that were "so much better than us" and that are music wasn't that good. She also made a remark about my younger brother's clothing (it was a flannel shirt and ball cap) stating that she didn't like them and that she hopes we wouldn't be performing in something ridiculous as such. I know that my little band isn't very good but we tried our hardest, and were very friendly, but I feel rather oppressed by the situation. I am losing inspiration because of it. I am just wondering if it is okay to be concerned with teachers upsetting kids even on a small scale?