A deeper look at the grooves pressed into Johnny Cash’s Record Store Day-issued Koncert V Prague LP. It’s incredible how great a difference ten years can make for a musician, but even more amazing is when it’s actually possible to hear that difference in their performance. In 1968, for example, Johnny Cash recorded his classic Live At Folsom Prison album; at the time, the singer was already developing a pretty serious drug problem (he’d become addicted to pills). It wasn’t...