Jonas Brothers and Backstreet Boys — two generations of boy bands — play back-to-back in Philly

Bringing together young men to harmonize sweetly and soulfully and dance in unison never goes out of style, a phenomenon apparent in sold-out Wells Fargo Center shows featuring the Backstreet Boys on Saturday and Jonas Brothers on Sunday.

While both began in different generations — Backstreet in 1993, Jonas in 2005 — each has thrived in the present, after some time off from the initial burst of fame. BSB continues to drop albums charting in the Top 10, including its latest, DNA, and the Jonases found themselves with their first No. 1 hit, “Sucker,” just this year. Yet each sounded the same as in the past.

BSB’s AJ McLean, Howie Dorough, Nick Carter, Kevin Richardson, and Brian Littrell may have teased themselves about missed gym workouts and old schoolboy band choreography during in-between song patter, but whether dancing or crooning, they operated with tight military precision and sang in crisp harmony, bobbing and weaving within one another’s phrases to make their signature brand of soul-pop.

Songs such as “I Wanna Be With You,” “Don’t Want You Back,” and “Everybody (Backstreet’s Back)” were BSB at their grandest, and their tech-heavy tone went handsomely with the DNA tour’s dramatic production of lights and hi-def screens on metallic funk numbers such as “Get Down (You’re the One for Me).” Each soloist was nuanced and rarely histrionic, especially on softer number such as the churchy soul of “Show Me the Meaning of Being Lonely” and the lovely “Shape of My Heart.”

While BSB ran through every smash — was this show really 34 songs long? — and recalled a Pennsylvania-based past of playing high schools, and their first Philly gig at the Electric Factory, this was no nostalgia act. They seamlessly included nine equally theatrical, yet warmly soulful songs from DNA.

Joe, Kevin, and Nick Jonas played things faster and looser than BSB come Sunday — a welcome surprise, considering how the JoBros had their own (often distracting) screen show unfurling behind them. Then, of course, there were the hydraulic-powered rising stage, lowered pianos, and the introduction of the trio, falling slowly from the sky with sparklers bursting behind them, then hitting the ground running, with the rocking, Celtic-inspired new “Rollercoaster.”

That was the first of many confident moves. Instead of getting the crowd warmed up with the old hits, they started with new songs like the soul-pop of “Cool,” featuring a signature Nick falsetto vocal, and the crankier “Only Human,” with the power pop of “S.O.S.” in between, the tangiest guitar licks courtesy of brother Kevin. It was a reminder of how the Jonas Brothers started life as a power pop outfit whose spunkiest, harmony-filled moments resembled the Raspberries (“Fly with Me,” “Burnin’ Up”) tinged with the Ramones when they punched their way through a medley “dedicated to all the original Jonas fans who stood in the rain for tickets” — “Mandy”/”Paranoid”/”Got Me Going Crazy”/”Play My Music”/“World War III”/“Hold On”/”Tonight.”

When it came to vocalizing, they hit the harmonies of “That’s Just the Way We Roll” with Everly-esque elegance. Joe and Nick mostly bobbed and weaved through each other’s solo lines, with one finishing his sibling’s thoughts on the throbbing, piano-heavy power ballad, “When You Look Me in the Eyes” and the syncopated soulful “I Believe.”

Joe and Nick did separately get chances to shine on their solo hits, created away from the family unit — a sultry “Jealous” courtesy of Nick, a deeply grooving and ebullient “Cake by the Ocean” from Joe’s band DNCE — as well as a series of acoustic numbers on a smaller stage. There, they not only took requests, and gave Joe his most gorgeous vocal moment on the new “Hesitate,” but offered a toast to “love and cheesesteaks.”

The Backstreet Boys and Jonas Brothers have grown up, handsomely, as men with genuine soul and deep, abiding harmony.