As the story goes, country slept with the blues in Memphis and gave birth to rock n’ roll. After a while, country got tired and went back to Nashville. And while that’s admittedly an oversimplification, a look at the intertwining history of the three genres reveals it to be an apt extended metaphor.

Following the split, the blues gave rock a mother’s unconditional love, nurturing it through its difficult stages and always providing a welcome return no matter how far it strayed from home. On the other hand, country and rock have had the type of relationship one would expect of a child and its absentee father. As rock entered its formative years, it rebelled against country’s old-fashioned ways – sometimes openly mocking it – and became more successful in the process. Once it grew up, rock reconnected with country in search of paternal guidance and wisdom. Meanwhile, country hasn’t always been willing to acknowledge its more successful offspring, but on occasion has had to embrace rock for the money.

All of which is a bit of a shame, because those moments when they’ve put aside their differences has resulted in some of the most enduring music of the rock era. But how did it get this way?

Hybrids of country and blues had been played throughout the South since the ‘20s, most notably Jimmie Rodgers and the Western swing popularized by Bob Wills and the Texas Playboys. But it wasn’t until the mid-‘50s, when electrified rhythm and blues – given the term “rock n’ roll” a few years earlier by Cleveland DJ Alan Freed – mixed with country (often then called “hillbilly music”) at Sun Records in Memphis to create a new sound, “rockabilly.”

How indistinguishable from country was rock at Sun Records? Less than three years after Elvis Presley’s initial success, Sam Phillips had signed the other three members of his “Million Dollar Quartet” – Carl Perkins, Johnny Cash and Jerry Lee Lewis. All three men were sonically similar to Presley and had tremendous success as country stars for decades without veering too far away from their original sound. Roy Orbison, another of Phillips’ rockabilly acts, got his start singing country hits in his high school band, the Wink Westerners.

But it wasn’t just at Sun where country combined with rock. Buddy Holly, like Orbison, grew up on country music and made the switch to rock after opening up for Presley a couple of times in 1955. At the same time, the Everly Brothers, whose parents were country singers with their own radio show, moved to Nashville and put their Louvin Brothers-inspired harmonies to some of rock’s earliest classics. “Wake Up Little Susie” and “All I Have to Do Is Dream” topped the pop, country and R&B charts. And you can’t forget about Gene Vincent’s “Be-Bop-A-Lula,” either.

Ricky Nelson may not have had the country roots of the others – his mother sang in the big band led by his father, and he rose to fame on their sitcom. But his hits like “Poor Little Fool,” “Lonesome Town” and “Hello Mary Lou” fit in perfectly with the country-infused rock and pop of the era. In the mid-‘60s, Nelson reinvented himself as a country singer and help usher in that era.

Watch Ricky Nelson Perform 'Lonesome Town'

Then came the British Invasion. In their early days, the Beatles proudly displayed their love of country and rockabilly. Their name was a play on Holly’s Crickets, they covered Perkins twice on record and some of their early songs, notably “Please Please Me,” “I’ll Be Back” and “I Don’t Want to Spoil the Party” showed how much they had learned about harmonies from the Everlys.

George Harrison would often talk about how his father’s Jimmie Rodgers records, especially “Waiting for a Train,” caused him to pick up the guitar, but Ringo Starr was the biggest country music lover in the group. In addition to his cover of Buck Owens’ “Act Naturally” on Help!, he used the genre for his initial experiments in songwriting – Rubber Soul’s “What Goes On” (a co-write) and the White Album’s “Don’t Pass Me By” (his first solo credit). His second solo album, 1970’s Beaucoups of Blues, was a collection of country songs cut in Nashville with some of Music City’s top session musicians.

But the Beatles were never fully committed to country and apart from the Hollies, who took their name from Buddy Holly and learned to sing from Everly Brothers records, none of the other major British Invasion bands showed much of a country influence upon hitting America. The Rolling Stones, the Kinks, the Animals, the Who and the Yardbirds (although Jeff Beck was a devotee of Gene Vincent’s guitar player, Cliff Gallup, and would release an album of Vincent covers in 1993) were all too devoted to putting their own take on blues or rhythm and blues. The Stones would eventually see the light, but as the British scene got heavier with the emergence of Cream, the Jimi Hendrix Experience and the Jeff Beck Group, blues became the lingua franca of rock.

Meanwhile, in America two developments had taken place by the mid-‘60s that also helped separate rock from country. On the pop-rock side of the equation, genres like soul, girl-group pop, garage rock and surf music had joined with the British Invasion to dominate the singles charts. Only folk-rock, which had a strong bluegrass influence thanks to Roger McGuinn’s banjo-like 12-string electric guitar playing with the Byrds, kept the country roots in rock.

Listen to 'Turn! Turn! Turn' by the Byrds

As for country, it had split into two factions. The “Nashville sound” – where traditional instruments like pedal steel guitar and violin were phased out in favor of strings and background vocals -- had more in common with mainstream ‘50s vocal pop than Western swing or rockabilly. As a reaction its slickness, a more traditionalist approach sprung up in Bakersfield, Calif., a town settled largely by Dust Bowl migrants looking for work in the nearby oil fields. Owens and Merle Haggard were the leading stars of the movement, which helped plant Southern California’s roots in country music – something that would pay off handsomely in time.

It took Bob Dylan to break the ice between the two camps. After sessions for Blonde on Blonde in New York didn’t go well, he moved operations to Nashville, where producer Bob Johnston brought in some younger session musicians who understood rock and R&B to back him up. While it would be a stretch to call Blonde on Blonde a country-rock record, the fact that Dylan, arguably the most important person in rock at the time, cut an album in the home of country music soon brought an influx of other musicians to Nashville. As Charlie McCoy, the multi-instrumentalist who starred on Blonde told Nashville Scene in 2011, “That's when the floodgates opened."

Dylan’s recuperation from his 1966 motorcycle accident proved valuable in bringing country and rock back together. He retreated to his home in Woodstock, N.Y., making music in the basement of a house where most of his backing group lived. When he resurfaced a year and a half later with the Nashville-recorded John Wesley Harding, it showed Dylan was inching closer towards country. He would deepen that connection in 1969 on Nashville Skyline, which featured a duet with Johnny Cash, with whom he had become friends in 1963.

His backing group had signed their own deal with Capitol and picked up the name of “The Band.” Although four of its five members were from Canada, they had gotten their start behind rockabilly singer Ronnie Hawkins. Furthermore, drummer Levon Helm was born and raised in Arkansas, and bassist Rick Danko had a heartbreakingly twangy voice that was perfect for country. They released their debut Music From Big Pink in 1968 and, coupled with its self-titled follow-up, musically and lyrically evoked the American South in the days before the birth of rock.

Music From Big Pink was so important that it even changed the mind of one of the staunchest blues purists of the day. Eric Clapton has gone on record as saying that it was one of the reasons why he broke up Cream.

“It sounded like they’d jumped on to what I thought we ought to be doing. That was what I wanted us to sound like and here was somebody else doing it,” Clapton later admitted. “It shook me to the core. … The Band had done it without even trying, and I harbored that as a weapon of resentment against Jack [Bruce] and Ginger [Baker] — who had a lot more respect for what we were doing than I did.”

Watch the Band Perform 'The Weight'

The Los Angeles folk-rock scene was also seeing the light, and it would become the home of country-rock. Buffalo Springfield’s brief tenure, which began in 1966, saw them lead the way, and they would soon splinter into Crosby, Stills, Nash & Young and Poco. In 1967, “Different Drum,” a song written by Michael Nesmith of the Monkees, was recorded by the Stone Poneys and reached No. 13 – launching the career of its singer, Linda Ronstadt.

But it was the kings of L.A. folk-rock who proved to be the most influential. After experimenting with psychedelic music and cutting ties with David Crosby and drummer Michael Clarke, the Byrds hired Gram Parsons, who convinced the band to record their next album in Nashville and bring elements of traditional country like barrelhouse piano and pedal steel guitar into the mix.

The result, 1968’s Sweetheart of the Rodeo, mixed material by such names the Louvin Brothers, Woody Guthrie and Merle Haggard with a couple of Parsons tunes and two unreleased Dylan songs. Along with Music From Big Pink, Sweetheart showed that country was as important to rock as the blues. However, the Byrds’ attempt to earn credibility when they played the Grand Ole Opry was met with contempt by the conservative Nashville crowd, who didn’t like the idea of a rock group playing the Ryman Auditorium.

“There was a stigma in those days in Nashville,” Roger McGuinn said in 2011. “We were fairly conservative-looking by the time we got to play the Grand Ole Opry. But by their standards, we had come from that hippie background. So, we were suspect as being Communist sympathizers or something. I don't know. But it was uncomfortable.”

Parsons had quit the Byrds by the time Sweetheart came out in August 1968, but while touring England with the Byrds, he met Keith Richards and the two became immediate friends. In his autobiography, Life, Richards said that “Gram taught me country music – how it worked, the difference between the Bakersfield style and the Nashville style. He played it all on piano – Merle Haggard, “Sing Me Back Home,” George Jones, Hank Williams. … Some of the seeds he planted in the country music area are still with me, which is why I can record a duet with George Jones with no compunction at all. I know I’ve had a good teacher in that area.”

Listen to the Byrds Sing 'Hickory Wind'

Richards’ introduction to country coincided neatly with what is widely considered to be the Rolling Stones’ best period, and they put their newfound knowledge to good use, albeit tentatively at first. Of the two country songs on Beggars Banquet, “Dear Doctor” was a goof and “Factory Girl” was heartfelt but slight.

But by Let It Bleed, they were more assured: “Country Honk” served as the blueprint for “Honky Tonk Women” and “You Got the Silver” was Richards’ first complete lead vocal on record. It blossomed on Sticky Fingers with “Wild Horses” and “Dead Flowers.” The entire second side of the two-LP Exile on Main St. – “Sweet Virginia,” “Torn and Frayed,” “Sweet Black Angel” and “Loving Cup” – was devoted to country-infused sounds. The Stones would flirt on and off with country from then on (most famously with “Far Away Eyes” on 1978’s Some Girls), but they would never be as successful with the genre as during that 1968-72 era.

During this time, Parsons continued exploring that sound where the lines between rock, folk, blues, country, soul and, to a lesser extent, gospel and traditional jazz were blurred, an idea he called “cosmic American music.” He formed the Flying Burrito Brothers and released two brilliant albums with them, The Gilded Palace of Sin in 1969 and Burrito Deluxe a year later, before being fired.

The work of Parsons, Dylan and the Band caused others in the late ‘60s to seek out the common ground within the numerous strains of American music. Even though they were from the Bay Area, Creedence Clearwater Revival – in sound and name – felt like a group from the South, and it’s not hard to imagine classics like “Lodi,” “Down on the Corner” and “Lookin’ Out My Back Door” being covered by country musicians.

Watch Creedence Clearwater Revival Perform 'Down on the Corner'

By 1970, as Creedence were winding down their period of chart dominance, their hybrid approach found a home, albeit with different sounds, in acts like the Doobie Brothers and Little Feat. Even the Grateful Dead scaled back their acid-drenched explorations to rediscover their roots with Workingman’s Dead and American Beauty. Across the Atlantic, Elton John’s third album, Tumbleweed Connection, was heavily inspired by the Band and the western films of John Ford. Over the years, he would frequently punctuate his records with country touches, such as the pedal steel guitar on “Tiny Dancer” or the barrelhouse piano of “Honky Cat.”

Another movement in bringing country back into rock took place in the South. The Allman Brothers Band’s 1969 self-titled debut set the template: Starting with a foundation in the blues, songs would take off into different musical directions via long jams performed by versatile virtuoso musicians. After the Allman Brothers broke through with their 1971 live double-LP, At Fillmore East, more bands followed suit. Within a couple of years, Lynyrd Skynyrd, the Marshall Tucker Band, Atlanta Rhythm Section and Black Oak Arkansas – all of whom had very deep country roots – would create the Southern rock movement.

As Southern rock was making inroads, a new aggregation of Los Angeles-based musicians were incorporating country music in ways that would come to define the genre.

35 Important Moments in Country-Rock History