participating in a performance artwork by james lee byars in the wide white space gallery (antwerp) in 1969 moved pink toward the visual arts. utrecht cultural deputy jan juffermans commissioned pink, opstaele and de groote (who became mass moving) to create an outdoor event in the city center. the result, "motion" (1969), was mass moving's first art intervention in an outdoor public space. a number of art-intervention projects on the scale of city life were created in public spaces in europe, africa and japan. in january 1976, at the end of the "sound stream" project, mass moving disbanded.