Sombr Brings Out 5 Seconds of Summer at Lolla 2026: Watch

Beyond the welcome surprise, Sombr himself commanded the stage alongside his band, strutting the T-Mobile mainstage, which featured New York street signs. A construction sawhorse suggested things were under construction, but onstage everything went off pitch perfectly, including his raw rock-to-falsetto vocals. He exuded confidence as he covered the full length of the stage, and later ran into the audience with a black flag spray-painted with his name and Lollapalooza.

The singer has been releasing a slew of new music recently, including “My Body Isn’t Ready” last month and also “Potential” and “Homewrecker,” all of which he performed during his Thursday set. The latter song made Rolling Stone’s best songs of 2026 so far: “The first post-breakthrough release from New York pop wunderkind Sombr is a hazy plea to a lover who has a partner waiting at home,” the review reads. “It glides on a lite-funk beat (with a bass line laid down by former Prince muse Wendy Melvoin) as Sombr lays out how he’s been strung along, including till-dawn fire-escape chats; while he’s sympathetic to his romantic rival, his all-in vocal indicates that he really, really wants to win.”

Sombr’s debut year has been nothing short of impressive. He released I Barely Knew Her last August and ever since, he’s captivated fans from his Grammy performance to his appearance at Coachella earlier this year, which featured Billy Corgan (whose band headlines Lolla tomorrow).

Following his performance at 2026 Lollapalooza, Sombr will embark on a North American tour this fall, which culminates with a show at Madison Square Garden in his hometown of New York on Nov. 23.