Gilbert "Gil" Scott-Heron (April 1, 1949 - May 27, 2011) was an American soul and jazz poet, musician, and author, known primarily for his work as a spoken-word performer in the 1970s and 1980s. His collaborative efforts with musician Brian Jackson featured a musical fusion of jazz, blues, and soul, as well as lyrical content concerning social and political issues of the time, delivered in both rapping and melismatic vocal styles by Scott-Heron. His own term for himself was "bluesologist", which he defined as "a scientist who is concerned with the origin of the blues". His music, most notably on the albums Pieces of a Man and Winter in America in the early 1970s, influenced and foreshadowed later African-American music genres such as hip hop and neo soul.

At the time of Scott-Heron's death, a will could not be found to determine the future of his estate. Additionally, Raquiyah Kelly-Heron filed papers in Manhattan, New York's Surrogate's Court in August 2013, claiming that Rumal Rackley is not Scott-Heron's son and should therefore be omitted from matters concerning the musician's estate. According to the Daily News website, Rackley, Kelly-Heron and two other sisters have been seeking a resolution to the issue of the management of Scott-Heron's estate, as Rackley stated in court papers that Scott-Heron prepared him to be the eventual administrator of the estate. Scott-Heron's 1994 album Spirits was dedicated to "my son Rumal and my daughters Nia and Gia", and in court papers Rackley added that Scott-Heron introduced me [Rackley] from the stage as his son." .  In 2011, Rackley filed a suit against sister Gia Scott-Heron and her mother, Scott-Heron's first wife, Brenda Sykes, as he believed they had unfairly attained US$250,000 of Scott-Heron's money. The case was later settled for an undisclosed sum in early 2013; but the relationship between Rackley and Scott-Heron's two adult daughters already had become strained in the months after Gil's death. In her submission to the Surrogate's Court, Kelly-Heron states that a DNA test completed by Rackley in 2011--using DNA from Scott-Heron's brother--revealed that they "do not share a common male lineage", while Rackley has refused to undertake another DNA test since that time. A hearing to address Kelly-Heron's filing was scheduled for late August 2013, but, As of March 2016, further information on the matter is not publicly available. However, Rackley still serves as court-appointed administrator for the estate, and donated material to the Smithsonian's new National Museum of African American History and Culture for Scott-Heron to be included among the exhibits and displays when the museum opened in September 2016.  According to the Daily News website, Kelly-Heron and two other sisters have been seeking a resolution to the issue of the management of Scott-Heron's estate. During the time Scott-Heron's 1994 album Spirits was being produced, he was living in Brooklyn, New York, with Nia and her mother.

Answer the following question by taking a quote from the article: Why wasn't there a clear lineage for the estate?
a will could not be found to determine the future of his estate.