The next part of my exploration as to what the 'fisherman saw at Lough Neagh is well served by this short extract by the composer Thomas Dunhill. His conclusion is that it was largely 'political' - which I guess disappoints me as i had assumed it to be mythological.
Stanford's Irish Rhapsodies, founded on the traditional airs of his native land, will, I believe, outlive all his longer orchestral works. No. 1 of these became obstinately popular to the exclusion of the others, a fact which so displeased him that he expressed extreme annoyance whenever he heard it was to be played. It is, nevertheless, a delightful work, though inferior at all points to No. 2, or the later "Ulster " Rhapsody, which is, perhaps, his most beautiful orchestral composition. None of the Rhapsodies are really rhapsodical.
They are skilfully developed movements, perfectly proportioned and balanced with the greatest regard for thematic cohesion. This is not, however, the really vital quality which distinguishes them. Nothing Stanford did, except some of his songs, makes so strong an appeal, by reason of the wild natural poetry which is in them. The scoring, too, is more inspired than that of the symphonies, more full of light and shadow, of colour and glamour.
. If I wanted to impress a foreign unbeliever with the real beauty of British music at its best I should take him to hear a performance of the "Ulster" Rhapsody, that he might have a glimpse of what the "Fisherman saw at Lough Neagh," and of what the great Irish composer was able to reflect of this vision in his music. "Dark and true and tender is the North" is the quotation attached to the closing page of the score-a mere expression of an Orangeman's sympathies, probably-but the three adjectives describe the loveliness of the music itself in a way that no other words could do. It is a work of imperishable quality.
From the Proceedings of the Musical Association, 53rd Session (1926 - 1927) with minor edits.
Irish Rhapsody No. 1 in D minor, Op. 78 (1901) made use of the Londonderry Air (Danny Boy) hence its one-time popularity.
Irish Rhapsody No. 2 in F minor, Op. 84 "The Lament of the Son of Ossian" (c. 1903)
Irish Rhapsody No. 4 in A minor, Op. 141 "The Fisherman of Lough Neagh and What He Saw" (1914)
Dunhill did not refer to the Irish Rhapsodies Nos 3, 5, & 6. There were still in manuscript at that time.