Willie Nelson goes behind the music in upcoming book

Willie Nelson fans are about to find out what was really on his mind while writing the hits that made him an icon.

Nelson, who turned 90 this year, is offering a behind-the-scenes look at lyrics from 160 of his favorite songs in a new book — “Energy Follows Thought: The Stories Behind My Songs,” set to release Oct. 31.

Nelson penned the book alongside David Ritz, who also co-wrote his 2015 memoir, “It’s a Long Story: My Life,” and harmonica player Mickey Raphael, who’s toured with Nelson since 1973.

The book will include songs dating back to the 1950s and cover backstories of his earliest efforts — some of which earned him a measly $50 — and his biggest hits. The book will also highlight some of his lesser-known songs, as well as his concept albums, of which he’s released five, including “Red Headed Stranger” and “Phases and Stages.”

Nelson will also be sharing stories about his beloved guitar Trigger, a Martin N-20 nylon-string acoustic that’s been with him since 1969. He’ll be diving into his family, as well as the Family — his recording and touring group since 1973.

Patsy Cline, Waylon Jennings, Ray Charles, Merle Haggard, Ray Price, Dolly Parton and other artists Nelson has collaborated with over the course of his career will also pop up throughout the book, along with never-before-seen photos and ephemera.

“Energy Follows Thought” will hit shelves days before the outlaw country musician is inducted into the Rock & Roll Hall of Fame on Nov. 3.

The book’s release will also stretch out the celebration of the “Crazy” singer’s 90th birthday. Festivities were in full force April 29 at the Hollywood Bowl where Kris Kristofferson, Neil Young, Snoop Dogg, Margo Price, Keith Richards and other music legends gathered to pay tribute.

Nelson will also be on the road again, touring until October with his traveling Outlaw Music Festival.