Johnny Cash and June Carter Cash were a delightful singing duo for reasons that had very little to do with the strength or quality of their voices (neither was, in the strict sense, a great singer). They were Johnny and June, a couple in love with the music they sang, and in love with each other, and that fact, their very devotion to each other, is why the sides collected here of their various duets over the years is such a delight. Country music is made of such things.