Given the following context:  Holst's settings of Indian texts formed only a part of his compositional output in the period 1900 to 1914. A highly significant factor in his musical development was the English folksong revival, evident in the orchestral suite A Somerset Rhapsody (1906–07), a work that was originally to be based around eleven folksong themes; this was later reduced to four. Observing the work's kinship with Vaughan Williams's Norfolk Rhapsody, Dickinson remarks that, with its firm overall structure, Holst's composition "rises beyond the level of ... a song-selection". Imogen acknowledges that Holst's discovery of English folksongs "transformed his orchestral writing", and that the composition of A Somerset Rhapsody did much to banish the chromaticisms that had dominated his early compositions. In the Two Songs without Words of 1906, Holst showed that he could create his own original music using the folk idiom. An orchestral folksong fantasy Songs of the West, also written in 1906, was withdrawn by the composer and never published, although it emerged in the 1980s in the form of an arrangement for wind band by James Curnow. In the years before the First World War, Holst composed in a variety of genres. Matthews considers the evocation of a North African town in the Beni Mora suite of 1908 the composer's most individual work to that date; the third movement gives a preview of minimalism in its constant repetition of a four-bar theme. Holst wrote two suites for military band, in E flat (1909) and F major (1911) respectively, the first of which became and remains a brass-band staple. This piece, a highly original and substantial musical work, was a signal departure from what Short describes as "the usual transcriptions and operatic selections which pervaded the band repertoire". Also in 1911 he wrote Hecuba's Lament, a setting of Gilbert Murray's translation from Euripides built on a seven-beat refrain designed, says Dickinson, to represent Hecuba's defiance of divine wrath. In 1912 Holst composed two psalm settings, in which...  answer the following question:  What suite written for military band remains a brassbands staple?
Answer:
E flat