Protesters and police clash in a blaze of color in British sculptor Tony Cragg’s 1987 piece ‘Riot’ a sculptural installation running the length of one of Lisson Gallery’s Chelsea spaces. Forty years ago, Cragg made a name for himself with artworks and installations composed of found plastic elements, a material that lacked the associations carried by more traditional media like bronze, marble or wood. Inspired by social unrest in ‘80s Britain, Cragg employs a modern material, fragmented and formerly discarded, to illustrate conflict between citizen and state. (On view in Chelsea through April 15th).