The Texas-based siblings show how they supported each after experiencing heartache and loss
willie and bobbie nelson
Credit: Todd V. Wolfson

For nearly 90 years, Willie Nelson and his older sister Bobbie have been by each other's sides while celebrating their success.

After Bobbie officially joined her brother's band as the group’s pianist in 1973, Willie Nelson and Family was born. Since then, they've performed more than a hundred shows a year, from honky-tonks to sold-out arenas.

"When we get into the music, something happens," Bobbie, 89, tells PEOPLE. "There's magic between me and Willie."

But their lives haven't always been easy.

For the first time, Willie, a 10-Grammy winner, and Bobbie ("the most naturally talented of all the Nelsons," Willie says) tell their previously untold story in a new joint memoir, Me and Sister Bobbie: True Tales of the Family Band.

me and sister bobbie

In 1986, Bobbie learned her son Michael was diagnosed with HIV. She took care of her son for three years before he died from AIDS. When she thought she couldn't feel lower, her oldest son Randy died in a single-vehicle accident six months later. As Bobbie grieved for her sons, Willie's oldest son Billy died in an accident the following year.

"I didn't really plan to share some of the things I shared," Bobbie says about her decision to tell her sometimes heartbreaking story. "There's a lot of things that happened during our lives, I would've never thought of explaining to someone. And now that it's happened, there's not anything for me to say except tell someone that you can survive.'"

Wille says some of the most difficult times in his life were difficult to share in the book.

"There's some things in there that I know [Bobbie] and I didn't really care to talk about," he tells PEOPLE. "I'm kind of a forgive, forget and move on kind of guy, and I don't really like to go back to it much."

After the loss of their sons, Bobbie says the pair grew closer.

"It wasn’t that we had long talks about our grief. That's not Willie's way. We didn't have to talk about it. We knew," Bobbie shares in their book. "I knew what Willie was going through. He knew how I was suffering. And the mere fact of being together made the burden a little lighter."

willie and bobbie nelson

For now, the 87-year-old Texas troubadour prefers to share his feelings through music and on stage, which was taken from him in March after the pandemic struck the country.

Willie has in mind a New Year's Eve show, ushering in Bobbie's 90th birthday on Jan. 1. "She's my closest friend for a whole lifetime," he says. "I'm glad she's getting some recognition for what she's done with her life."

To read an excerpt from their book Me and Sister Bobbie: True Tales of the Family Band, pick up this week's issue of PEOPLE, on newsstands Friday.