Carrie Underwood has unleashed a third track from her upcoming new album, Storyteller. The new song, "What I Never Knew I Always Wanted," is about both her baby boy, Isaiah, and her husband, NHL hockey player Mike Fisher.

"What I Never Knew I Always Wanted" is a slower, almost dreamy tune. It is the final track on Underwood's new project and was written by the singer, along with Brett James and Hillary Lindsey. The first verse takes its inspiration from Underwood's relationship with her husband, while the second is inspired by their son.

"I finally found what I never knew I always wanted / I couldn't see, I was blind 'til my eyes were opened," Underwood sings in the chorus. "I didn't know there was a hole, something missin' in my soul / 'Til you filled it up with your love ..."

“I never dreamt of my wedding day and the perfect guy. Then I met Mike, and I was like, ‘Wow, so now I know what I was missing,'" the country superstar tells People. "And the same with my son. I was never like, ‘I want kids so bad.' And now that I have Isaiah in my life, I’m like, ‘What did I do before?'”

Although she says that she “kind of tried to stay away from” writing about her new baby, Underwood has admitted that "it just kind of happened one day.”

"It’s impossible to not let your life affect things," the singer says.

"What I Never Knew I Always Wanted" is the fourth song from Storyteller that Underwood has shared. Fans who pre-order the album will receive the tune, along with “Renegade Runaway,” “Heartbeat” and the album’s first single, “Smoke Break,” as instant downloads.

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