Keith Sonnier (1941-2020) was a postminimalist sculptor, performance artist, video and light artist. Sonnier rose to prominence in the late 1960s with a practice that was highly experimental and of the moment. His use of neon in combination with ephemeral materials gained him early international recognition. Sonnier’s use of unconventional materials—from industrial neon to ephemeral, high-tech radio waves and tactile, soft elements, such as flocked latex and foam rubber—impelled him to reimagine sculpture as something to be experienced beyond the merely optical.