In 1989, "The Learning Tree" was among the first 25 films deemed "culturally, historically, or esthetically significant" enough to be included in the National Film Registry for future preservation. Parks' second feature, "Shaft" (1971), actually had a far greater cultural impact. A major commercial success, the gritty NYC-lensed black detective story was one of the key early films in the 70s "Blaxploitation" movement. "Shaft" generated a hit theme song, two sequels (the first, 1971's "Shaft's Big Score," was also helmed by Parks) and a TV series. Continuing to work in the action genre for the next several years, Parks displayed increasing technical and narrative proficiency and was rewarded with bigger budgets for his efforts. What was missing was the personal and committed elements in evidence in "The Learning Tree." He recaptured some of those qualities in "Leadbelly" (1976), a fine if somewhat sanitized biopic about legendary blues singer Huddie Ledbetter.Perhaps Parks' most accomplished film, "Leadbelly" boasted a strong and charismatic central performance by Roger E. Mosley (best known as laid-back helicopter pilot T.C. on TV's "Magnum, P.I."), great music and awe-inspiring cinematography from Bruce Surtees. Produced by a tax shelter group and copyrighted by a Netherlands entity, the film failed to find the large audience it so richly deserved due partially to poor marketing and distribution but moreover because young modern filmgoers neither knew nor cared about the subject. This turned out to be Parks' swan song as a feature director.Parks went on to write several volumes of poetry and fiction. An accomplished self-taught pianist, he composed a number of piano sonatas, a symphony and other works for the concert stage. Parks directed and composed music for several interesting projects for PBS in the 80s (the 1984 historical drama "Solomon Northrup's Odyssey" and the autobiographical documentary "Gordon Parks: Moments Without Proper Names" and ushered in the 90s with "Martin" (PBS, 1990), an original, five-movement ballet about the life of Dr. Martin Luther King. Parks served as executive producer, director, composer, keyboardist and documentary photographer for this boldly ambitious project. Father of the late director Gordon Parks Jr, who was best known for "Superfly" (1972).