There are at least four bands called The Proof:
These are photos from concerts where The Proof played, so they may be of other bands that played the concert as well.
Pat Benatar / The Proof Oct 11, 1980 Upper Darby, Pennsylvania, United States Uploaded by Zimtrim
Pat Benatar / The Proof Oct 10, 1980 Passaic, New Jersey, United States Uploaded by Zimtrim