Singer Willie Nelson performs during an “In Performance at the White House” series event. (Jacquelyn Martin/AP)

As Veterans Day approaches, the Washington air thickens with rock-star serenades.

With droves expected on the Mall for Tuesday’s Concert for Valor — a rock/rap/R&B/country/pop extravaganza honoring American veterans — the White House hosted a more exclusive, elbow-roomier tribute concert Thursday night.

“A Salute to the Troops: In Performance at the White House” continues the venerable concert series that the Obamas launched in 2009 — a series that seems to have lost momentum over the past year.

Don’t worry. The president still digs music.

“We’ve got a little bit of rock-and-roll, we’ve got a little bit of country, a little bit of everything in between,” President Obama said in his opening remarks to an audience largely made up of military families. “And that’s good, because here in America, no matter where you are from, no matter what music you listen to, we’re all united out of respect and admiration for the brave men and women who wear our country’s uniform.”

President Barack Obama speaks at 'A Salute to the Troops: In Performance at the White House'. (Olivier Douliery/Pool/EPA)

And so Thursday night’s lineup was put together with genre diversity in mind. Beneath a massive tent pitched on the South Lawn of the White House, Mary J. Blige sang stately soul, Romeo Santos crooned tender bachata and John Fogerty ripped through his indelible songs of protest as if the Vietnam War were still raging.

The common thread here was gravitas, which Willie Nelson radiated instantly and effortlessly. When the 81-year-old country outlaw-turned-deity opened the show with his casually defiant “We Don’t Run,” the audience began clapping out a beat before the backing band had time to get to work.

Forgerty’s performance, though, was easily the most riveting. With a trademark red handkerchief cinched around his neck, he blasted through “Bad Moon Rising” and “Fortunate Son,” the latter a scalding protest anthem Forgerty wrote in 1969, back when a different White House was overseeing a different war.

More subdued was Common, the Chicago rapper who, thankfully, didn’t have to suffer much manufactured fuss from the conservative pundits who pounced on him when he was booked to perform at the White House in 2011.

Three years later, he was back on Pennsylvania Avenue — but instead of rapping, Common recited a poem while bandleader and super producer Don Was plucked jazzy phrases from an upright bass. It raised a tangential but important question: In 2014, is rap music still too controversial to be performed at the White House?

As earnest as Common was Daughtry, the rock band led by former “American Idol” finalist Chris Daughtry, which delivered soft-rock balladry via satellite from Yokota Air Base in Japan. Also sincere, back beneath the White House tent, were performances by such active-duty military members as Christiana R. Ball, an Army sergeant, and Matt Smith and John Ed Auer, both Marine captains.

After opening the show, Nelson came back to close it, leading the ensemble, and Obama, through a sing-along of “On the Road Again.”

It felt jovial and carefree — but for military families often separated by countless miles of roads and ocean, perhaps a little bittersweet, too.

“A Salute to the Troops: In Performance at the White House” (one hour) airs Friday at 9 p.m. on PBS stations nationwide.