Leigh sings it himself, quite beautifully. He performs a handful of his other hits and takes questions. I ask him which comes first to him during songwriting, the melody or the lyrics?
"The mortgage," he says.
We bus on to another shrine to country music, the Ryman Auditorium (ryman.com), built in 1892 as a concert venue. From 1943 to 1974, the gorgeous wooden structure hosted the Grand Ole Opry, the nation's longest-running radio show. The Saturday night show now emanates from a new hall, but the Ryman is still in use as a performance space and, that night, we attend a country show there.
Next stop: Memphis, Tennessee. It is where, in 1968, civil rights leader Martin Luther King Jr was shot and killed by a sniper at the Lorraine Motel. The National Civil Rights Museum (civilrightsmuseum.org) has been built around the motel.
Our guide, Mr Roy Logan, 71, takes us through the exhibits. The multi-sensory experience, which includes a diorama of a slave ship, reveals how blacks in the US, especially in the South, rarely earned their rights because whites were suddenly enlightened. Rather, those freedoms were gained only after confrontation and struggle, often at the cost of the lives of black protesters and white allies.
It is only in retrospect, decades later, that most people view the old Southern caste practices to be obviously unjust.
Mr Logan's passion when speaking of the struggle makes the exhibits come alive.
The retired teacher, who is black, talks about his own experiences. He says he was awakened to injustice in 1955 when he learnt of how a 14-year-old Mississippi boy, Emmett Till, was lynched for allegedly flirting with a white woman. "I was the same age as him. I grew up in Memphis. Later, when I got a car, people told me never to go to Mississippi," he says.
Memphis is also home to blues music and its famed Beale Street area downtown is filled with dozens of bars with live bands. A place that attracts great musicians is B.B. King's Blues Club (bbkings.com/memphis), where you are as likely to hear soul and funk as blues.
It also serves diners upstairs, with a menu specialising in local cuisine: slow-cooked ribs, beef brisket, pulled pork and, of course, fried chicken.
For lunch, I eat crunchy, spicy fried chicken, washed down with a cup of orange soft drink, at Gus's World Famous (gusfriedchicken.com), a restaurant launched 60 years ago in Tennessee, which has now become a chain in the South and West.
Memphis is ranked among the most crime-ridden areas in the US. The group's hotel, the Westin Memphis Beale Street (www.westinmemphisbealestreet.com), is just around the corner from the party zone, so walking to the bars is fairly safe if done in groups. At night, the police are out in force on Beale Street.
Presley-heads should visit the legendary Sun Studio (sunstudio.com), which bills itself as "the birthplace of rock 'n' roll". Like Studio B in Nashville, Sun is a working studio which sets aside time for tours. Here is where much of the original gear from the 1950s has been preserved.
Guide Nina Jones, 22, lets our group touch and pose with the microphone used by Presley, Jerry Lee Lewis, Carl Perkins and Johnny Cash. Hip-swivelling and helicopter arms are optional.
No tour of the South should exclude touching on its most distinct historical trait: slavery.
Located close to the Mississippi River, in Louisiana, Frogmore (frogmoreplantation.com) is a working cotton plantation, a 728ha thriving business with the big machines needed to raise the crop that, more than anything else, made the South the South.
Frogmore is unique in that the farm's 1800s slave row is mostly intact. Its owner and guide, Ms Lynette Tanner, walks our group through the wooden buildings. It housed 58 families, mostly of black slaves and a few white overseers.
The household goods preserved there tell the story of cotton, slavery and the Civil War. They also speak of clothes, worship, marriages, music and food - the stuff that daily life is made of, for both slaves and their masters.
Ms Tanner talks about the 2013 movie 12 Years A Slave and the scene in which one slave is whipped for bringing in an underweight sack. She shows us the sack.
"Each slave had to bring in 75 pounds (34kg) of cotton, four times a day," she says.
The cotton and sugar trades that flourished on the back of forced labour gave rise to a mercantile class who would build opulent homes known in local slang as "sugar palaces". Our tour makes a stop at one of the most well-preserved, Houmas House (houmashouse.com).
In its ornate rooms and lush gardens, we take in a lot of history as well as the mildly eccentric decor style of its current owner, industrialist Kevin Kelly.
Another home of note is Monmouth Historic Inn and Gardens (monmouthhistoricinn.com) in Natchez, Mississippi. In this stately manse-turned-hotel, our group stays one night, some of us in the main building (built in 1818) and others in the more recently built cottages, decorated in 19th-century style.
If walls could speak, Monmouth's would speak of antebellum wealth, easy living for its owner thanks to slaves, and family fortunes plunging after the South lost the Civil War.
The walls might mention former slaves returning to work as paid staff, post-war, and of its falling to rot in the 20th century before new owners, in the 1970s, began a restoration to get it to its present magnificent state.
And, no, nobody on the bus says anything about seeing a Civil War ghost.
At the bar in Monmouth, bartender Roosevelt Owens demonstrates his version of the classic Southern cocktail, the mint julep. His trick is to sweeten the potent, refreshing cocktail - he uses Amaretto and Creme de Menthe - with honey, Sprite and sugar. He then serves it in a silver mug.
The next stop is New Orleans. A local guide hops on board our bus and gives a narrated tour of the city's high points before taking the bus to the place where history, lifestyle and religion come together: the cemetery.
At St Louis Cemetery No. 3, our guide Robbie uses the tombs - their heights, styles of ornament and sizes - to give a quick and engaging summary of the social history of the port city.
Tombs are built above ground because of the city's waterlogged soil, for example, and a family tomb can be used for many generations because when new bodies are put in, older ones are taken out and cremated.
At the New Orleans School of Cooking (neworleansschoolofcooking.com), chef Kevin Belton gives demonstrations for classic Creole dishes such as gumbo, a hearty soup with African origins.
He says the secret to gumbo is perfectly browned roux, or flour cooked in oil, a technique much trickier than it sounds. The other secret is file (pronounced fill-ay), ground dried sassafras leaves, for flavour, and like the roux, used for thickening.
Chef Belton advises us to go to Frenchman Street for good jazz, rather than stick to the French Quarter, where we are likely to get watered- down stuff. We opt to play it safe and have drinks at Fritzel's European Jazz Bar (fritzelsjazz.net) in the French Quarter. The band play good, competent ragtime and old-school stuff.
In the afternoon, we hop on the last operating paddlewheel steamboat on the Mississippi River, Steamboat Natchez (steamboatnatchez.com), for a leisurely ride, complete with a lunch buffet. The engine room is open to visitors and engineer Ken Howe is happy to talk about what it takes to keep the ancient machine running.
Dinner on the last night of the Southern Grace tour is at Arnaud's (arnaudsrestaurant.com), a fine-dining spot with jazz players roaming between tables.
It serves alligator sausage, oysters, gumbo and crab cakes. It is a lovely setting to top off a memorable trip - even if you are not a Presley fan.
• The writer was hosted by Insight Vacations