i_o is the pseudonym of Los Angeles-based electronic musician Garrett Lockhart. While often known for producing dark, driving tracks such as the self-explanatory "Death by Techno" (2019), he also makes lighter, more uplifting progressive house material, particularly collaborations with Tommy Trash and Daisy Guttridge like 2017's "Oxygen."

Generally veiled in secrecy, i_o first emerged in 2017, appearing on the We Are Friends, Vol. 7 compilation released by Deadmau5's Mau5trap Recordings, and co-producing Tommy Trash's "Oxygen." Several i_o tracks appeared on Mau5trap and InHarmony Music in 2018, from the bright, accessible progressive house of the Rootkit EP to the warehouse-ready techno of Fatal Error. Another collaboration with Trash and Guttridge, "Let Me Go," appeared in 2019 followed by the singles "Death by Techno" and "Truth" (with Jauz), as well as the House of God EP. Garrett Lockhart died on November 23, 2020 at the age of 30, only two days after releasing a video for his single "Castles in the Sky." ~ Paul Simpson, Rovi