Even Merle Haggard gets nervous about stepping onto a stage when the audience is filled with songwriters, record label executives and fellow artists.

"Well, it's glorious but it's also tough because all the pressure is on you," Haggard said after recently playing two sold-out nights at the Ryman Auditorium in Nashville, Tennessee. "You've got all those people out there that call you a legend and an icon and all that stuff. You kinda gotta prove it."

But judging from the cheering and ovations, Haggard — who helped create the twangy electrified Bakersfield Sound in country music — still knows how to impress a crowd.

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At 77, he tours the country about two weeks each month and recently bought a new tour bus, a sign that he's not interested in retirement from the road. His band, the Strangers, now includes his wife, Theresa, and 21-year-old son Ben, as well as band leader Norman Hamlet, who has been with Haggard since the 1960s.

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"It's real tempting to let it all go, but it's taken many years to get to where I am at," Haggard said. "To divorce myself of it earlier than I have to is really not something I want to do."

Haggard had lung surgery after a cancer diagnosis in 2008, and he said an early, but incorrect, diagnosis had him thinking he had only a short time to live.

"And then they told me, 'No, we're wrong. It's only just a little benign condition that we can get rid of,'" Haggard said. "It was sort of a disappointment. I was ready to go."

But Haggard said he hasn't had any recurring symptoms, so he's not dwelling on past health problems.

Born outside of Bakersfield, California, in 1937, Haggard, the son of Oklahoma migrants, was raised in a converted railway boxcar, the only home his family could afford. Famous for his prison stint in San Quentin, Haggard said music was his only opportunity out of poverty.

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"My decisions have been easy," he said. "It was either back in the cotton patch or go to work in the oil fields. ... They didn't compare with music. I was able to make more money in a beer joint when I first started than I was digging ditches."

The gruff, baritone-voiced singer became known for his classic tunes about drifters, convicts and blue collar workers, including "Okie From Muskogee," ''Mama Tried" and "Workin' Man Blues." But he said that after writing some 700 songs, it's hard to find a subject he hasn't written about yet.

Haggard even took a playful poke at a common topic for current country music: romance blossoming in the back of a pickup truck.

"There seems to be love songs written about mechanical items," Haggard said with a smile. "I never thought about using a tractor as some way of getting laid."