It was just six months ago that The Alabama Shakes played a free show during the W.C. Handy Music Festival.

Now, the Athens foursome is selling out venues across the country.

On Tuesday, they will make their national television debut on “Conan,” the late night talk show hosted by comedian Conan O’Brien. The program airs at 10 p.m. on TBS.

The Alabama Shakes is led by the soulful voice and rhythm guitar of Brittany Howard, who is joined by Heath Fogg on lead guitar, Zac Cockrell on bass and Steve Johnson on drums.

Shoals keyboardist Ben Tanner also has performed with the band.

“It’s unreal to be playing on national television, and I’ll be pretty nervous,” Fogg said in an email to the TimesDaily.

The band just completed a sold-out West Coast tour that included a show at the legendary Troubador in West Hollywood, Calif.

Later this month, the band will play three sold-out shows at the Boston Arms pub in London, then return to the U.S.

A March 31 show at the Workplay SoundStage in Birmingham is sold out, but tickets remain for a March 23 show at the Bama Theater in Tuscaloosa.

The band’s debut full-length album, “Boys & Girls,” is being released April 10 on ATO Records.

Fogg said the band never expected this much attention.

“I feel blessed that so many people love the music we love to make,” he said. “The past few months have been extremely busy, but it has been a dream come true.”

The band’s popularity exploded shortly after it was featured on the independent online music blog, Aquarium Drunkard, which also has a weekly show on Sirius/XM satellite radio. The band opened several shows for The Drive-By Truckers after its appearance in Florence.

Fogg said while the schedule has been hectic, the best part about the tour is traveling around the country and seeing new places.

“I have gotten to see parts of the country I’ve wanted to see my whole life, and getting to play music in these places makes it that much better,” Fogg said.

While the band was in Los Angeles, it performed a set during the KCRW radio show, “Morning Becomes Electric.” Two days later, the band was interviewed on National Public Radio’s “World Cafe.”

The band is set to appear at the Sasquatch Festival in George, Wash., in May.

Russ Corey can be reached at 256-740-5738 or russ.corey@TimesDaily.com.