By Vernell Hackett

NASHVILLE (Reuters) - Country singer Alan Jackson is known for telling true-to-life tales but he says a song about his wife's battle with cancer, "When I Saw You Leaving (For Nicey)," was tougher than most.

In fact, he admits it was the hardest tune he's ever had to record.

The heartfelt song about Denise, his wife of 30 years, is the closing track on Jackson's newly released album "Thirty Miles West" and it keeps with the country music tradition of writing about the realities of life.

"I wrote it right after we found out about her cancer, but I didn't want to play it for her then," Jackson told Reuters. "A year or so later, when everything was okay and after we recorded it, I played. Like most of the people who hear it, she cried."

Jackson, 53, is one of country's top artists and made his name in 1990 with debut album "Here in the Real World." Dozens of hits have followed, including "Midnight in Montgomery," "Small Town Southern Man," "Good Time" and "Chattahoochee."

The Grand Ole Opry member also wrote the Grammy-winning hit "Where Were You (When the World Stopped Turning)" which attempted to make sense of the September 11, 2001 attacks and their aftermath.

Even with all that experience, Jackson said the first one or two times he tried to record "When I Saw You Leaving," he couldn't get through it because he was overcome with emotion.

"I finally got it," he said. "I tried to write it so that it would be something other people could identify with, because so many people have been through those same emotions and experiences."

LOVE, LIFE AND COUNTRY

"So You Don't Have to Love Me Anymore", Jackson's current single from his new album, was co-written by his nephew Adam Wright and Jay Knowles. It is currently in the top 30 on Billboard's country music chart and climbing.

He said his nephew is a bit like himself, "not too pushy and he's modest about his stuff," so Jackson must ask him to play new songs each time he enters the studio. "When I heard this song, the hairs stood up on my arm," Jackson said.

Similarly, the opening track, "Gonna Come Back as a Country Song" sounds like it came straight from Jackson's songbook, but he had little to do with the tune, which talks about coming back as a country song and hanging out in honky-tonks every night.

One tune Jackson did write, "Look Her In the Eye and Lie," is something he swears he never had to do with a woman.

"I don't know where that line came from. I keep these pieces of paper around so that whenever I hear something or think of an idea for a song I can write it down," he said. "That line had been on my list since my last album, and I just pulled it out and wrote it."

Not all the numbers on "Thirty Miles West" have sad themes.

"Dixie Highway," recorded with Zac Brown, is about a stretch of 200-year-old road that runs from Michigan to South Florida. Jackson said he heard about it while fishing in Florida, and he was intrigued by the history of the road and the people who live along it. And it seemed a perfect tune for Brown.

"It's about the rural south and the small towns and how life is very similar in all of them," he said. "It's about eight minutes long and has seven or eight verses and a lot of pickin'!"

And while the tune "Life Keeps Bringing Me Down," co-written by Jackson's former fiddle player Shawn Camp and Al Anderson, may seem dark due to its title, the song is a fun tune with a lot of energy behind the music.

"Thirty Miles West" was released on June 5, and Jackson is supporting the album with a three-month U.S. tour.

(Reporting Vernell Hackett, Editing by Jill Serjeant, Bob Tourtellotte and James Dalgleish)