Who cares? Apparently more than 8,000 fans.

A misty, drizzly drawl settled over Berkeley on June 5, with clouds holding the sun hostage. Despite the gloomy afternoon, it seemed like all forces were in favor of Rex Orange County’s Berkeley show of his “Who Cares?” tour. The sky cleared at dusk, and the only thing drenching the Greek Theatre was giddy anticipation.

Excited screams burst from the floor to the fields above, teeming with buzzing fans as they caught glimpses of Rex Orange County (Alexander James O’Connor) behind the stage. Finally, the curtains drew back just a sliver, and O’Connor stepped out with a knowing smile.

Sheer delight filled the air as he waved to the crowd, eyes bright and almost in disbelief as he scanned the masses. He donned a vibrant orange jumpsuit, an outfit synonymous with the singer’s bright and eclectic music.

O’Connor is best known for his take on bedroom pop, his music embodying a trademark and upbeat melody contrasted with earnest lyrics. He sings of growing pains — from feeling awkward and anxious to depressed and lonely. Though his songwriting hasn’t changed, there was a certain debonair to the singer’s Berkeley performance that signaled a joyous growth in confidence and charm.

“Making time/ Just to see you,” O’Connor sang, pointing to the crowd with a cheerful insistence as he performed “Making Time.” The curtains then drew back, revealing his band and a large-scale cow-print backdrop with doodled figures from his album art. Massive LED letters spelling out “Who Cares?” hung in the air, reflecting Rex Orange County’s hallmark quirk and vibrance.

“What’s up, Berkeley? Are you ready?” O’Connor asked with a grin, dancing and jumping to the sanguine melody of “Keep It Up.” His energy was larger than life, and he knew it.

The singer made fast friends with the crowd, turning his performance into a dynamic game. Affectionately instructing the audience to belt choruses and wave its hands, O’Connor not only performed for his fans but with them too.

His performances were anything but minimal, with everything from revamped arrangements to animated sets. Yet O’Connor’s stellar musical range still took charge. Particularly, his distinct vocals took centerstage during his soulful crooning in “One in a Million,” where he took to the keyboard for the track’s slow start.

O’Connor also kept the humble spirit of his bedroom pop, with a few tracks spotlighting only his voice and impressive guitar riffs — just like the old days. He shuffled his setlist with newest hits as well as anthems from his earlier discography that put him on the map.

“I want you to go f—ing bananas,” O’Connor said, intensely serious about having fun. He gave “Sunflower” — arguably his most famous song — an epic tribute, complete with glorious trumpet riffs and a set change involving tall, colorful flowers with disco-ball centers. Wasting no time, he launched into another crowd favorite, “Best Friend,” making for the most memorable performance of the night.

Until this point, the crowd was a flurry of cellphones and flashlights as everybody tried to capture their favorite songs live. Then, O’Connor made a request during “Best Friend”: He asked the audience to put away devices for the latter half of the song.

“No phones, just human beings,” he said, smiling and chasing the purest connection with his fans at this moment.

What followed was a gleeful (and undocumented) dance party as the audience reveled in this rousing track. O’Connor kept spirits insurmountably high. He relished the crowd, throwing his hands in the air triumphantly as he incited riotous singing and sheer euphoria. Gasps peppered the audience as large beach balls of every color launched into the pit, bouncing in the air.

Dialing the energy down to a sweet, wistful end, “Pluto Projector” served as the show’s apt encore. Though O’Connor sang of bliss and the honeymoon phase, it was clear he was sad to leave the stage.

“I hope the encore lasts forever,” O’Connor sang in a bittersweet goodbye.