I'm going to drop my choir's tour
Why do you want to?
I'm really intimidated by the skills of others in my choir.
Don't you care about how the others in your choir might feel? What if they were counting on you?
It's not like they can do it without me. Besides, I'm in college now, I'm a big girl now.
Dropping out of an important event is unfair to those who've put effort and time into it. If you've made a commitment to something you should follow through. If need be you can make time for both school and your previous engagements.