The 41 poems, which were discovered by Johnny's son John Carter Cash after his dad's death age 71 in 2003.

They are to be sold in a collection called Forever Words: The Unknown Poems, some of which date back as early as 1944, when Cash was just 12 years old. The poems are included with reproductions of the handwritten originals.

In the foreword to the poetry book, Carter Cash wrote, "My father had many faces. There was much that made up the man. If you think you “know” John R. Cash, think again. There are many layers, so much beneath the surface."

The 46-year-old, who like his father, and mother June Carter Cash is also a musician, wrote that despite his father's downbeat public persona, due in part to his decision to always wear black on stage, he was a joyful man.

"To those who knew him well - family, friends, coworkers alike -the one essential thing that was blazingly evident was the light and laughter within my father’s heart. Typically, though his common image may be otherwise, he was not heavy and dark, but loving and full of color," he explained.

However, some of the poems in Forever Words are deeply personal. You Never Knew My Mind from 1967, captures the Walk the Line singer's bitterness during his divorce from Vivian Liberto, while Going, Going, Gone, from 1990, is about his drug abuse: “Liquid, tablet, capsule, powder / Fumes and smoke and vapor / The payoff is the same in the end.”

Carter Cash added that he felt the poems reflected his dad's personality better than his music did, writing, "When I hold them, when I touch the pages, I can sense my father in some ways even more profoundly than in his music."

The poetry collection is available now, and is published by Penguin Random House.