But Folsom had specific qualities that served the recording well. Its cafeteria, with approximately 2,000 inmates, was large enough to create the effect of a genuine crowd but contained enough that Cash’s performance could reach every corner. The concrete walls created an acoustic environment that Johnston’s close-miking approach addressed without entirely eliminating — the slight echo in the recording is audible and contributes to the feeling of a specific space.
Folsom’s history also gave the setting a specific weight. It was opened in 1880 and was, by 1968, one of California’s oldest and most historically significant prisons. It had housed some of California’s most dangerous criminals and had been the site of substantial documented brutality over its history. It was, in short, a serious place — the kind of maximum-security facility that the phrase “prison concert” actually meant, rather than a minimum-security facility where the term would have had different connotations.
Cash had been performing at prisons since 1957. He had played Huntsville, San Quentin, and other facilities over the following decade. He understood, by 1968, the specific dynamics of a prison audience: the intensity of attention, the lack of distraction (inmates at a prison concert have nowhere else to be and nothing competing for their attention), the gratitude for entertainment in a setting that provided almost none. He had performed for these audiences enough times to know what worked and what didn’t, what songs landed and which fell flat, how to read a crowd that expressed itself in ways different from a civilian audience.