Convert B2 to B1 for a singing competition!?

[Kate Luu]

I'm in the US now with B2, can I change my B2 to B1 for a singing competition to have enough time to complete it?
My B2 visa will expire before the competition finish and the organization said that they can just only write a letter for me that prove I'm joining the competition now.
I don't know if B1 is the right visa?

[newacct]

I'm in the US now with B2, can I change my B2 to B1 for a singing competition to have enough time to complete it?
My B2 visa will expire before the competition finish and the organization said that they can just only write a letter for me that prove I'm joining the competition now.
I don't know if B1 is the right visa?

Your visa will expire? or your status, as given on your I-94, will expire? US visas are only for entry and when it expires is irrelevant once you are in the US.