Curator, gallery owner, theorist, textile scholar and collector Seth Siegelaub died, age 71, in Basel, Switzerland, on June 15. His longtime partner Marja Bloem confirmed his death in an e-mail to A.i.A. In the 1960s, Siegelaub was an early proponent of Conceptual art and developed novel ways of presenting these new art forms to the public.

Although his New York gallery, Seth Siegelaub Contemporary Art, was short lived, remaining open only from 1964 to '66, its impact was not. While still in his 20s, Siegelaub worked with artists such as Joseph Kosuth, Robert Barry, Lawrence Weiner, Carl Andre, Robert Morris and Douglas Huebler on experimental projects and exhibitions in which there were often no actual objects produced. Siegelaub tried various unorthodox curatorial approaches to the material; sometimes he displayed in his 56th Street gallery documentation of the various performances, actions and ephemeral interventions by his artists, and, in other instances, record of the works existed only in the form of gallery publications. In interviews in later years, Siegelaub described the gallery as a collaborative effort with an emphasis on projects that had little or no commercial prospects.

Born in the Bronx, New York, Siegelaub attended Hunter College and entered the art world as a part-time assistant at the Sculpture Center before opening his gallery. In the later 1960s, his interests shifted to leftist politics and to artists' rights. In 1971, he co-authored with lawyer Robert Projansky, "The Artist's Reserved Rights Transfer and Sale Agreement," which would pay artists a royalty whenever their works were resold at auction or elsewhere. The proposal for such a legally binding agreement between artists and galleries was far ahead of its time and remains a contentious art-world topic today.

The following year, Siegelaub abandoned New York and the art world and settled in London, where he concentrated on leftist media studies. In more recent decades, he focused his attention on the history of textiles and became a major collector and scholar in the field. A number of exhibitions of selections from Siegelaub's textile holdings have appeared in the UK, most recently at London's Raven Row Gallery last spring.