Look closely at the man in the cream suit, caught mid-crouch with his guitar slung low across his hips, and you are not watching a photo session. You are watching a movie. The front of After School Session is a single frame lifted from Chuck Berry's performance in the independent film Rock, Rock, Rock! (1956), a still pulled from motion and pressed flat onto cardboard.

Berry leans into the shadows of a stage, his pale suit glowing against folds of dark backdrop, his white shoes planted wide on a floor that catches a sickly olive light. His mouth is open mid-phrase, his eyes cut sharply to one side, his body coiled in the kind of pose you can only freeze, never hold. The hollow-body guitar hangs dark across him, his right hand near the strings. Everything in the posture says this man was moving a half-second before the shutter caught him.

A name in blue, a fistful of slanted staff lines, and a frame stolen from celluloid: how did a movie still end up standing in for a studio portrait, and why does it still read as pure sound?