How to keep my best friend from coming to this concert?

A concert is a public event, not something just for you and your friend. If your other friend wants to go then let her. It sounds to me like your shy friend is afraid of change.

You made the mistake - I think the stand-up thing to do is honor this with your Best friend - ‘go behind her back’ next time if that’s important to you and you don’t want to include her.

ask your best friend if shes gotton a ticket yet ((if its one of those concerts..not just pay at the door or w/e)) or like say you got into trouble and cant go. you could just tell her bluntly that since you two hang out all the time you feel you should hang out with another friend for a change if she has a problem with it then shes not that good a friend, she should be able to accept that you want to hang out with diff. people its not like your going to dump her away.

I hope you know that the best thing to do is “politely” let your friend know that you had made plans already with someone else and that other person is really shy and doesnt do well meeting new people. The best thing to do is tell her the truth. But if thats to much for you, then I guess you can get your parents in on it. When your best friends over, do something your parents dont let you do (let your parent know before though) then make one of them tell you in front of her that you can no longer go to the concert. Maybe she’ll get the idea? I dont like lying to people, but if you’re ok lying to your best friend, then thats the only thing I can suggest.

^ good answer!

just tell her why you really picked your friend instead of your bff!