Charles Kelley

Charles Kelley performs during Charles Kelley In Concert at Gramercy Theatre on December 1, 2015 in New York City.

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The key to Charles Kelley’s new single, "Lonely Girl," can be found at the end of the second line in the song. As the Lady Antebellum member stretches out the last word -- "We used to be so in looove" -- there’s an enormous tension in the moment. There’s something distinctly wrong about it, at least within country traditions, but it’s that part that’s "wrong" that makes it feel so right.

"All the rules kind of go out the window with this song," Kelley told Billboard of the song. 

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That’s for sure. "Lonely Girl" spends an uncommonly lengthy 34 seconds of its three-minute run in the bridge, a segment that a lot of songwriters won’t even put in a modern song. It’s a first-person lyric in which the "person" isn’t really a human at all. And then there's the matter of that melodic tension, created in part because the verses of "Lonely Girl" alternate over a two-chord pattern that is rooted more in jazz and R&B than country.

"That whole verse is really dissonant," said songwriter Jesse Frasure (Florida Georgia Line's "Sun Daze," Rascal Flatts' "I Like The Sound of That"). "It kind of rubs in a lot of ways."

At the heart of that dissonance, said producer Paul Worley (The Band Perry, Big & Rich), are a pair of major seventh chords. They essentially extend a standard three-note major chord with one extra note that falls a half-step below the root. The note that Kelley sings at the end of that second line is the dissonant one and it cries out for resolution, which doesn’t actually arrive until the end of the fourth line.

"It's teasing you," said Worley. "That's the magic of a major seventh chord."

Used only sparingly in country, the major seventh is key in such familiar songs as Smokey Robinson's "Ooh Baby Baby," Marvin Gaye's "What's Going On" and Sixpence None the Richer's "Kiss Me." And it’s that soul/pop tension -- and inevitable release -- that makes "Lonely Girl" such an addictive experience.

"It starts off with this kind of James Bond-ish feel and in the chorus goes into this total Hall & Oates, Maroon 5-type thing," noted Kelley. "It’s just a bit of a head trip and I think that’s what makes the song so interesting."

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Frasure and Chris Stapleton wrote "Lonely Girl" around 2011 on a bit of a lark. During a dinner at Nashville's Cabana, Stapleton's wife, Morgane, and Frasure's wife (then-girlfriend), Red Vinyl senior creative director Stevie Frasure, challenged the guys to write together. They accepted the dare that night -- Stapleton showed up well after dark at Major Bob Music and lugged a stand-up bass into Frasure's office.

It was a lot of effort for an unlikely payoff -- Stapleton could only play one riff on the instrument. But they recorded that riff and turned it into a loop with two alternating major seventh chords, forming the basis for the verses. Those stanzas in turn set up a celebratory chorus.

"I like choruses that open up, that explode into something else," said Frasure. "We had this moody thing, but if you stay there, you're just going to stay in sort of jazzy land, so we kind of wanted to open it up a little bit."

They changed it up one more time at the bridge, dropping the intensity and slowly powering back up through sheer repetition.

All along, "Lonely Girl" used a deceptive lyric, consoling a broken-hearted woman with a promise that "I'm never gonna let you down/When you need me, I’m always gonna be around." It sounds like the perfect man, when in reality, it's possibly the perfect song. It's the record speaking to her, almost like audio porn, vowing to satisfy her emotional needs while being whatever she projects onto it.

"It is a little ethereal," said Frasure. "It's that unconditional thing that’s always there whenever you want it."

Stapleton sang lead on the demo -- he sounds a whole lot like Terence Trent D’Arby on the bridge -- and did some counter vocals that serve as an answer to the lead. They pitched it to a few obvious pop artists -- Bruno Mars, for example, passed on it -- but Frasure found a champion when he sent "Lonely Girl" to Kelley, who thought it would be great for Lady Antebellum. Bandmates Dave Haywood and Hillary Scott weren't so enthusiastic, but Kelley held on to it several years, finally deciding to throw it on what he thought would be a solo EP when he was recording in 2014.

Funny thing about the timing -- Thomas Rhett had recorded the Motown-inspired Stapleton/Frasure song "Crash and Burn" and all of a sudden several major artists wanted to cut "Lonely Girl." Frasure called Kelley to check on the song and Kelley assured him it had a destiny -- likely as a single.

Initially, Kelley and Worley cut "Lonely Girl" with a live studio band, replacing all of Frasure's programmed instruments on the demo with real players. Abe Stoklasa, who co-wrote "The Driver," played a sax solo. But when that version missed the mark, Kelley suggested using the demo itself. Frasure's synthetic percussion and retro keyboards remained. So did Stapleton’s counter-vocals and -- on the verses anyway -- his stand-up bass riffs.

Kelley gave an impassioned read, personally challenged by the quality of Stapleton's soul-steeped performance on the demo.

"The verse is easy," said Kelley, "but what's hard is that chorus. You've got to get after that chorus. It was hands down the most challenging vocal on the record."

Kelley stacked his vocals and Worley brought in a small string section, stacking it as well to create a sort of classic, Philly soul sound on the bridge. Worley played additional rhythm guitar and popped a solo into the background on the outro.

"I'm actually playing 'Amazing Grace,'" he said. "It didn't really occur to me until after I played it, and I was like, 'Oh, shit, nice.'"

The final step was to add a second bass into the mix. Craig Young stayed away from the verses, where he might clash with Stapleton’s stand-up, but he added some thump in the choruses and a few extra melodic runs.

Based on fan reaction, "Lonely Girl" became the obvious second single from Kelley's solo debut. It's perhaps the best example to date of the blue-eyed soul that has always played a role in his performances and it comes at a time when country is exploring R&B through such singles as Rhett’s "Die a Happy Man," Chris Lane’s "Fix," Zac Brown Band's "Loving You Easy" and Brett Eldredge's "Lose My Mind."

"People have been interested in the blend of soul and country certainly for the last few years," said Worley. "It's finally starting to rise to the surface."

Capitol released “Lonely Girl” to radio via Play MPE on March 31. It rises 56-52 on Country Airplay, providing a different shade of Kelley than he has been able to express through his primary gig.

"This sounds different than anything I did with Lady A and that was the goal," he said. "I wanted to make sure that I respected the fact that Lady Antebellum does this. If I’m going to do a solo record, it better stand on its own. Otherwise, why do it?"