Dance and movement aficionados can celebrate, explore and interrogate 50 years of the distinctive dance form of Contact Improvisation (CI) at “Redux Forward” — a pair of events on July 11 and 12 at Open Space for Arts & Community.

The event will include a performance of the pivotal 1991 CI work, “Swim/See/No Sea,” as well as a lecture-demonstration and multimedia jam, ritual and community event.

The weekend will be led by two highly accomplished longtime practitioners of the dance form, Vashon-based Karen Nelson and Brooklyn, New York-based K.J. Holmes.

At 2 p.m. Saturday, June 11, joined by local dancers and Seattle multi-instrumentalist Evan Straus, Nelson and Holmes will perform their duet, “Swim/Sea/No See,” which was devised and performed in the early 1990s in North America, Europe and South America. A lobby installation, detailing the history of the dance form and including an archival display of “Contact Quarterly,” an influential journal of the form, will be on view at 1 p.m.

That afternoon, Nelson and Holmes, in a discussion moderated by islander Joan Hanna, will also share early video footage of CI and their duet, describe their dance form in light of its 50-year history, and hold an audience talk back after their performance.

CI is a post-modern partner dance form that emerged in 1972, based on the principles of gravity, body weight, momentum, and trust.

Calling their dance form a “cinema of the body,” Nelson and Holmes have also incorporated the distinctive practices of improvisation and observational composition, called “tuning scores,” into their work.

They describe their work as one involving “constant questionings about musicality and the theater of dance.”

At 11 a.m. Sunday, June 12, Nelson and Holmes will present “CI Interrogates And Tunes Itself,” where the public is invited to take part as participants, observers, or both. During the three-and-a-half-hour event, Nelson and Holmes will guide a warm-up, and screen videos curated to examine the past, present, and future of CI. A ritual element of the presentation will provide “a space for each dancer to claim and share their own origin and identity story in their own dance experience.”

This event will also include archival video footage from Diverse Dance Research Retreat, an initiatory program that brought dancers with and without disabilities to Camp Sealth on Vashon from 1993 to 2000, for a multi-day conference and performance sharing. The footage will also include works by Ishmael Houston Jones, mayfield brooks and the late artists Fred Holland and Nancy Stark Smith. These clips will lead to dance improvisation, ensemble dancing, and observance from an audience perspective.

Tickets to “Swim/Sea/No See,” on June 11, are $20 to $40. Tickets to “CI Interrogates And Tunes Itself” are $30 to $50. No one will be turned away for lack of funds.

More information is available at explomov.weebly.com, and tickets can be purchased at openspacevashon.org.