Task: Question Answering
Input (English): Passage: During and after the composition of The Planets, Holst wrote or arranged numerous vocal and choral works, many of them for the wartime Thaxted Whitsun Festivals, 1916–18. They include the Six Choral Folksongs of 1916, based on West Country tunes, of which "Swansea Town", with its "sophisticated tone", is deemed by Dickinson to be the most memorable. Holst downplayed such music as "a limited form of art" in which "mannerisms are almost inevitable"; the composer Alan Gibbs, however, believes Holst's set at least equal to Vaughan Williams's Five English Folk Songs of 1913.Holst's first major work after The Planets was the Hymn of Jesus, completed in 1917. The words are from a Gnostic text, the apocryphal Acts of St John, using a translation from the Greek which Holst prepared with assistance from Clifford Bax and Jane Joseph. Head comments on the innovative character of the Hymn: "At a stroke Holst had cast aside the Victorian and Edwardian sentimental oratorio, and created the precursor of the kind of works that John Tavener, for example, was to write in the 1970s". Matthews has written that the Hymn's "ecstatic" quality is matched in English music "perhaps only by Tippett's The Vision of Saint Augustine"; the musical elements include plainsong, two choirs distanced from each other to emphasise dialogue, dance episodes and "explosive chordal dislocations".In the Ode to Death (1918–19), the quiet, resigned mood is seen by Matthews as an "abrupt volte-face" after the life-enhancing spirituality of the Hymn. Warrack refers to its aloof tranquillity; Imogen Holst believed the Ode expressed Holst's private attitude to death. The piece has rarely been performed since its premiere in 1922, although the composer Ernest Walker thought it was Holst's finest work to that date.The influential critic Ernest Newman considered The Perfect Fool "the best of modern British operas", but its unusually short length (about an hour) and parodic, whimsical nature—described by The Times as "a brilliant puzzle"—put it outside the operatic mainstream. Only the ballet music from the opera, which The Times called "the most brilliant thing in a work glittering with brilliant moments", has been regularly performed since 1923. Holst's libretto attracted much criticism, although Edwin Evans remarked on the rare treat in opera of being able to hear the words being sung. 
Question: What is the name of the set of songs that Alan Gibbs believes is at least equal to Vaughan William's Five English Folk songs of 1913?
Output (English): the Six Choral Folksongs of 1916.