Do you need to get permission to perform a cover song in public?
This varies depending on country and/or state but as long as you are not profiting from it directly and in a public setting like a street corner or a park then you should be okay. However, If you are performing at a venue or facility which has a copyright music license (e.g) ASCAP, then you may be required to pay a fee(s). This is only because if that venue has registered with ASCAP, they’re legally obligated to make note of the music of any artist covered by ASCAP which has been played within their establishment.