The Johnny Cash Children's Album (Sony, 2006)

Compared to "Personal File", this month's other Cash release, "Children's Album," Cash's curious 1975 record now being reissued, inhabits a far less crucial corner of his ultimate musical legacy, but it sure is a lot of fun. Of course, by nature it should be - and there's much more levity on "Children's Album" than "Personal File." But Cash sneaks in plenty of lessons along the way. The tone of the record is lighthearted and playful, but he manages to interject tales of the common man ("The Timber Man") and relay intimate portraits of those he cherished most ("Grandfather's Clock").

Rick Rubin produced four installments of man-alone-with-guitar albums that redefined Johnny Cash's career in its twilight. Those recordings used a similarly stripped-down format with more familiar songs, and that allowed them to achieve greater universal appeal than these new offerings. They show an artist at an unlikely peak. But "Personal File" and "Children's Album" should rank alongside them in historical importance. These shed rare light on the man behind the guitar.