Daryl Hall and John Oates can't go through the motions. No can do.  It would be easy for the septuagenarians to just play the familiar since one of the most pop duos in music history have a staggering 34 chart hits on the Billboard Hot 100.

However, when vocalist-keyboardist Hall and vocalist-guitarist Oates returned Saturday to headline the second annual Hoagie Nation at a hot and sticky Festival Pier, the tandem offered some extra mustard in their sonic sandwich.

Anyone who has witnessed his consistently entertaining web series "Live From Daryl's House," knows that Hall loves to jam with a variety of musicians. Train and Fitz and the Tantrums, who have appeared on "Live From Daryl's House" were part of the Hoagie Nation lineup.

Patrick Monahan of Train performs during Hoagie Nation at Festival Pier.
ELIZABETH ROBERTSON / Staff Photographer
Patrick Monahan of Train performs during Hoagie Nation at Festival Pier.

Train's Pat Monahan appeared during Hall & Oates two-hour set. Monahan delivered a pair of Train tunes with H&O, "Calling All Angels" and "Wait for Me." A nice touch because Train's half-hour set, which was interrupted by a 20-minute weather delay, was awfully short.

"Pat and I sing really well together," Hall said. The charismatic frontmen not only connect as singers but as songwriters.

"Philly Forget Me Not," a recently penned tune by Hall, Oates and Monahan, was rendered. It's a tip of the cap to the city where Hall and Oates met while attending Temple University during the '60s.

The catchy soulful pop track earned a roar from the crowd sweltering under the Festival Pier canopy. The crowd, primarily comprised of baby boomers, also approved of the groove-laden gems of such hits as "Sara Smile" and "I Can't Go for That (No Can Do)." The latter featured a new rap. "We live in strange times / We all have our breaking points."

But Hall & Oates have never had a breaking point.  The pair, who will hit the half-century mark in 2019, are unlike many of their peers. The pair never broke up and Hall, who grew up in Pottstown and Oates, who came of age in North Wales, still exude warmth after all of these years.

They smiled at each other during Oates' solo obscurity "Is it a Star."

Hall & Oates were at their best while playing the hits, such as the bouncy "Kiss on My List" and the infectious closer for the 16-song set, "You Make My Dreams."

Longtime multi-instrumentalist Charles DeChant, who has played with Hall & Oates since 1976, is the act's unsung hero. DeChant impressed behind the keyboards, on the saxophone, and during a flute solo during the epic "I Can't Go for That."

Hall looks great for a 71-year old. He still brushes his blonde hair back in the same manner as he did during the band's heyday. However, Hall is judicious when it comes to hitting the high notes. Like an aging major-league hurler, Hall reached back and went to the falsetto during "You Make My Dreams."

Michael Fitzpatrick of Fitz and the Tantrums performs during Hoagie Nation at Festival Pier.
ELIZABETH ROBERTSON / Staff Photographer
Michael Fitzpatrick of Fitz and the Tantrums performs during Hoagie Nation at Festival Pier.

Both Train and Fitz and the Tantrums, who played the undercard of the festival, had shorts. During Train's set, Monahan couldn't resist pandering. "Will you please go crazy and let me take a video so I can put it on Twitter," Monahan asked the audience, who complied.

A generation ago, Rolling Stone tabbed Tommy Conwell and the Young Rumblers, who played earlier in the day, as the next big thing out of the East. It didn't work on a national scope for Conwell, but the gritty singer-songwriter is a local staple. Conwell and his Rumblers are no longer young but the energetic band engaged the enthusiastic group of fans hoping for regional radio hits from the '80s.

Marty Stuart and his Fabulous Superlatives were a nice change up from the pop-rock. Stuart and his band showcased its country tunes while bantering with audience.

There's the Temple University connection between Mo Lowda and the Humble and Hall and Oates. Lowda and the Humble, which formed at Temple, delivered a powerful set of tunes filed between alt and prog rock.

West Philly's emerging  Beano French dropped the soul. The young, charismatic entertainer just doesn't serve up moving R&B. It was evident that French possesses presence and a welcome swagger.

Since it was Hoagie Nation, the iconic sandwich co-starred. There was a hoagie eating contest and Cosmi's Deli's stand was busy. The shop, which is based at 8th & Dickinson, sold well into the triple digits, with the Santa Fe Turkey fire-roasted peppers the most popular choice.

According to John Oates, Hall and Oates will be back for the annual event in 2019.