Celebrities and stars are truly only fun to look at before they harden into their “look.” Marilyn Monroe when she was more Norma Jean than Marilyn. Katherine Hepburn up through about Bringing Up Baby. Cary Grant when he was still goofy looking.

This is particularly true in the case of Johnny Cash. Well into his career, before he trademarked the Man in Black look, Cash looked more human--more vulnerable, unsure of himself, fierce in some photographs and gentle in others.

Nowhere is this more obvious than in Johnny Cash at Folsom and San Quentin, the late Jim Marshall’s photographs of Cash’s historic performances at two California’s prisons in 1968 and 1969.

The recordings of these performances rejuvenated Cash’s stalled career in majestic fashion. The San Quentin album became a crossover hit for the country singer, reaching number one on the pop charts. In midlife, Cash became a superstar.

But in these photos, none of that had quite happened yet. He was still loose enough to shoot a bird at the camera (Marshall supposedly asked the singer for “one for the warden.”), and he still didn’t have his wardrobe quite sorted out (a blue turtleneck keeps popping up in some shots).

Here there’s a raw, unselfconscious energy here that you miss in late-era Johnny, whether he’s rehearsing, performing, or just shaking hands with the inmates. His excitement is palpable and infectious, so much so that for once, the pictures of these concerts are as exciting as the recorded performances they compliment. Thank goodness Jim Marshall was there to capture it all.