A terrific compilation of Cash's work at Sun Records between 1955 and 1958. Some of these--"Ballad of a Teenage Queen" being the most famous--find the Man In Black backed by vocal groups such as the Jordannaires, leaving them sounding like period pieces. Most of the rest of this stuff, however, is stripped down, fatalistic country and rockabilly, which sounds like nobody else before or since.
It's impossible to overstate how eerily minimalist and spooky a song like "I Walk the Line" seemed when first released; a lot of people just weren't ready for Cash's sepulchural vocals and those seemingly random modulations from verse to verse. Nothing else here is quite this left-field, but there are several other classics, including the original version of "Folsom Prison Blues" (there is still no more chilling line in American pop music than "I shot a man in Reno just to watch him die"), and the often-covered "Get Rhythm."