The Planets dedication notwithstanding, Imogen Holst "would have been both amused and dismayed by the venture." On 24 August 2006, the International Astronomical Union (IAU) defined what it means to be a "planet" within the Solar System. This definition excluded Pluto as a planet and added it as a member of the new category of "dwarf planets", along with Eris and Ceres. Following the IAU decision, Kenyon D. Wilson composed a trombone quintet piece titled "Songs of Distant Earth". The title comes from Arthur C. Clarke's novel of the same name. The composition contains five movements, each named after one of the
Gustav Holst scherzo movement of a projected symphony, contains features characteristic of much of Holst's earlier music—"a summing up of Holst's orchestral art", according to Short. Dickinson suggests that the somewhat casual collection of material in the work gives little indication of the symphony that might have been written. Holst made some recordings, conducting his own music. For the Columbia company he recorded "Beni Mora", the "Marching Song" and the complete "Planets" with the London Symphony Orchestra (LSO) in 1922, using the acoustic process. The limitations of early recording prevented the gradual fade-out of women's voices at the end of "Neptune", and