Willie Nelson's Outlaw Music Festival pulled into Camden's BB&T Pavilion on Saturday with a stacked bill featuring not just one but two bona fide all-time great songwriters and song interpreters.

In addition to the reassuringly spry 85-year-old paterfamilias of the tour, who closed out the nine-hour show with a crisply efficient 60-minute set with his family band, there was another still-vital elder statesman in the amphitheater.

That would be Northern Ireland soul man Van Morrison, who joined Nelson for the final date of his four-show run on the Outlaw tour. It was the rarely touring Morrison's first show in the Philadelphia area since playing the Tower Theater in 2008. (He did do a show at Hershey Park Stadium last year, also with Nelson.)

The two living legends did not sing together. But seeing them back-to-back at the end of a six-act bill that included sets by Tedeschi Trucks Band, Greensky Bluegrass, Lukas Nelson & the Promise of the Real and Particle Kid, was a rare treat. It was also an opportunity to observe the methods of two supremely confident masters at work.

Willie Nelson performs during the Outlaw Music Festival at the BB&T Pavilion in Camden on Sept. 15, 2018.
ELIZABETH ROBERTSON
Willie Nelson performs during the Outlaw Music Festival at the BB&T Pavilion in Camden on Sept. 15, 2018.

Nelson, who has been in the news because he's playing a show this week in support of Beto O'Rourke, a Democratic U.S. Senate candidate, is of course casual in the extreme. His Martin acoustic guitar, Trigger, is beaten and battered. After the Texas state flag unfurled behind him at the start of "Whiskey River," he rolled into the Zen wisdom of "Still Is Still Moving To Me," and tossed his cowboy hat into the crowd during Waylon Jennings' "Good Hearted Woman."

He's a country singer down deep in his bones, of course, and he did three Hank Williams songs on Saturday. But Nelson's music has always leaned toward the fluidity of jazz and lonely night saloon singing. His newest album is a set of big band Sinatra songs called My Way, and one of the highlights of his Saturday set was his tender guitar solo on gypsy jazz guitar great Django Reinhardt's "Nuages."

Nelson’s Martin acoustic guitar, Trigger, is beaten and battered.
ELIZABETH ROBERTSON
Nelson’s Martin acoustic guitar, Trigger, is beaten and battered.

Nelson's band included his sister Bobby on piano, longtime affiliates Mickey Raphael on harmonica, and Paul English on drums, plus sons Lukas on guitar and Micah (who is Particle Kid) as a second drummer. The familial feel was further developed when the members of Greensky Bluegrass, whose complete-with-Pink Floyd covers set early in the day was a crowd favorite, came on stage for a closing sing-along on the the gospel standard "I'll Fly Away." (Greensky Bluegrass are playing the new North Broad Street venue The Met Philadelphia on Jan. 11.)

Like Sinatra, Nelson is an articulator and an enunciator. His genius as a stylist lies in his unpredictable, conversational phrasing. That's in contrast to the equally improvisational Morrison, who tends to ride the rhythm of his soul, R&B and blues songs, luxuriating in the sound, always one step away from scat singing.

The improvisational Van Morrison is always one step away from scat singing.
ELIZABETH ROBERTSON
The improvisational Van Morrison is always one step away from scat singing.

But while his approach is more diffuse, Morrison is also more formal, as he takes to his task of diving into the mystic with a strict sense of discipline. Dressed in a shiny pinstripe suit and wearing shades and a porkpie hat, the 73-year-old Belfast native fronted a fabulous nine-piece band that featured trumpet, vibraphone, violin, sterling backup vocalist Dana Masters and Van the Man himself both blowing harp and tootling away on saxophone when he wasn't singing in a burly, robust voice.

There was clearly no preordained set list in effect, so the question was: Will he decide to perform the hits? He did, or at least enough of them from his '60s and early '70s commercial heyday over the course of a 90-minute set to keep the crowd happy. A jazzy, finger-snapping "Moondance" and "Wild Night" kicking up an energetic storm on a marvelously comfortable Camden evening, and just when you thought he might be sneaking away, coming back onstage for a two-song encore of "Brown Eyed Girl" and "Gloria."

Just as satisfying as those numbers, though, were the deep catalog renditions that came in the meat of the set, which flowed without interruption from one tune to the next — with absolutely no between-song chatter.

Often they were the result of Morrison keeping the band on its toes by calling a song title without a moment's notice, whether for the sorrowful "Sometimes We Cry," from 1997's The Healing Game, or "Precious Time," from 1999's "Back On Top." On John Lee Hooker's "Think Twice Before You Go," Morrison not only took great pleasure in letting out Hooker-esque "howl, howl, howl, howl," the exacting band leader even let it be known that he was pleased with his fellow musicians with a two-word review of their performance: "Very nice."

Tedeschi Trucks Band preceded Morrison, playing a loose-limbed, 90-minute set of their own. The 12-member blues rock ensemble fronted by Susan Tedeschi and husband Derek Trucks displayed an impressively varied musical arsenal, with three horn players and three backup vocalists in addition to the most formidable duo of married guitarists in music.

Tedeschi Trucks connect to the Allman Brothers tradition that is Trucks' birthright — he's the nephew of the late drummer Butch Trucks — and through his liquid, effortlessly flowing lead guitar work. They also put forth a rugged gospel and R&B blues sound that shows up in Tedeschi's soul-shouting vocals.

Most appealing is the familial vibe of the diverse, gender-balanced band, which has six October dates coming up at the Beacon Theatre in New York.  B-3 player Kofi Burbridge shone on the the churchy, wailing "Bound For Glory" from 2011's Revelator. Tedeschi was showcased as a singer, but all the vocalists had a chance to shine, particularly on a warm and wonderful take on Ray Charles's "Let's Go Get Stoned."

The band's connection to history and the history of the Camden venue were underscored in Tedeschi's spoken intro to a winning cover of Tom Petty's "You Don't Know How It Feels," always a popular choice for its "let's get to the point, let's roll another joint" lyric.

"Derek told me a story about Tom Petty meeting Gregg Allman at this venue," Tedeschi said, referring to a 2006 date when Trucks was a member of the Allmans and the two covered Willie Dixon's "Little Red Rooster." "Let's hope they're playing somewhere together."