“Good Morning America” launched its free 2019 Summer Concert Series on Wednesday in Central Park with K-Pop supergroup BTS, and the crowds were predictably massive.

Diehard lovers of the Korean boy band camped out for days, with some sleeping on 72nd Street since Friday for the opportunity to witness them in the flesh. Organizers say they haven’t seen such a fever pitch of fan worship since the Backstreet Boys and Beyoncé performed, ABC reports.

Fans — many of whom refer to themselves as “A.R.M.Y.” or “Adorable Representative M.C for Youth” — also slept on the street in hopes of seeing the “Bangtan Boys” in April, when BTS performed on “Saturday Night Live.”

The group’s massive IRL fan base naturally translates into huge social media power, including 17.8 million Instagram followers and 18.5 million YouTube subscribers. The group’s music videos have collectively been watched over 2.5 billion times. Among US states, the group currently is streaming the most in Hawaii, California and Nevada, according to Spotify.

BTS recently became the first band since The Beatles to earn three chart-topping Billboard albums in one year with their latest release, “Map of the Soul: Persona.”

“I mean, we’re all fanboys of [The] Beatles, of course, who is not?,” lead singer RM, a k a Rap Monster, said on the morning show. “We feel so honored to be with the greatest names in the music industry.”

Next up to perform in the “GMA” Friday summer concert series, now in its 11th year, is Hozier on May 24, followed by Ellie Goulding, Blink-182, Chance the Rapper and others lined up through the end of August.