For most of his tragically short career, i_o displayed an innate understanding of dance music at its most timeless. Born Garrett Falls Lockhart in 1990, the Virginia native started crafting punchy electro-house as FAWKS before launching his i_o project in 2017, recording trance-influenced songs for labels like Spinnin’ Deep and deadmau5’s mau5trap. His big break came with 2019’s “Violence,” a shimmering electro-pop anthem co-written with Grimes. Then, before he died of thyroid disease in 2020, he released his three-part magnum opus: ACID 444, NRG 444, and AM 444, dedicated to the classic sounds of mind-melting acid, pummeling techno, and uplifting trance. The series proved i_o a savvy channeler of dance music’s enduring energy. In 2022, Armada released the posthumous Warehouse Summer—an expansive showcase of his talents and a heartbreaking suggestion of what might have been.