(Cover) - EN Showbiz - Jay-Z has revealed how he ended up comparing himself to Che Guevara.

In a new book entitled Decoded, set for release in November, the 40-year-old rap star lifts the lid on some of his more unusual song lyrics.

Whilst promoting the tome, Jay-Z has explained how he came up with the rhymes to his interlude Public Service Announcement (PSA) from 2003's coveted The Black Album.

The rap superstar compares himself to Argentine Marxist revolutionary Che Guevara in the interlude, and has admitted that came about after hed caused a stir for wearing a T-shirt with the political icons face on it teamed with a jewelled crucifix.

The second verse of PSA may not have that many hidden jewels in [it], but the story behind why I wrote the second verse is pretty interesting, he told MTV.

It's sort of that look on rap, how this writer had written this article about me wearing this Che Guevara shirt [with a] Jesus piece, and she was like, 'The Jesus piece is hitting his head,' and I was like, 'You're going a little too far. It's a T-shirt and a chain. It's not literally hitting his forehead,'

"That [experience] inspired the entire verse. 'I'm like Che Guevara with bling on, I'm complex.' It's the whole entire story of how and why I came to write that second verse on 'PSA.' "

Jay-Z also said he hopes people reading the book will come to understand rap music isnt superficial. The talented musician considers himself and other rap artists to be politically engaged poets as well as masterful lyricists.

"[I want to show] that rap is really poetry; it's not just a bunch of guys putting rhyming words together. There's thought behind it and there's cleverness and there's inspiration, he explained.

There's social reason and there's political reason and there's angst and there's anger and all these different things inside music. (C) Cover Media