do you need to be in a high school band to get into a music university?

I am 15 and play guitar. i want to get into a music school, such as Berklee or Musicians Institute. I know a good amount of music theory and can read music fairly well. I am not in a high school band or orchestra . Is this going to affect my chances of getting into a music school?

No

Most guitar and piano majors have never been in band or orchestra. You will need to have been in “a band” of some sort though for the experience unless you’re planning to become a soloist.

HIGH SCHOOL BAND – Trailer