Lyrics in annotations.
I have had a lot of fun researching into this song, finding out what the lyrics where about given vague info, making up my mind what they where about, researching online and in books I have for reference, coming up with interpretations and then doing the same for the pictures shown. The basic info is that Black Finn is Fionn mac Cumhaill, leader of the legendary warriors known as the Fianna, even the Irish national anthem odes to them. Finn's son is called Ossian, he's sort of a Irish pantheon god whose a bard, so the death of him in the song/poem talks of the loss of culture.

I only found out about Iarla Ó Lionáird from going to a Concern fund raising concert (Ireland's biggest charity organization). I have to say it was one of the most powerful symphony/orchestra performances I've ever seen. In this recording the “uilleann pipes” take up most of the droning but to hear an orchestra play it is something I will never forget. For me the room actually became dark and I had no control over my posture, it was an experience I only have when deep into meditation.

The paintings are unrelated to the music yet for me go together perfectly in there own way. This song by the title appears to be mourning of a loved one (Oisín, son of Fionn mac Cumhaill). The lyrics/poem reveals that it is actually a personification of the loss of ones civilization and way of life, therefore the apocalyptic scenes make sense for me. I was thinking first of a digital picture of dark Celtic fantasy, then of showing an image of Oisín but decided to base it off what felt right and not what was right, funny since that is the Romantic fashion of logic “not thinking but feeling”. The paintings/engravings are by the Irish Romantic painter (John Martin).

I would love to decipher then meaning behind the lyrics, having a thin line between mythology and historic personification of politics. Unfortunately I'm not that educated in my own countries history/mythology. I can say that I know much more of other mythologies and history then I do of my own.

I only started properly looking into Irish mythology early Winter 2015, a new role play group (D&D5E) I was invited to started up so I had to make a character. I wanted to base my character on the god Lugh (father of the famous Cú Chulainn), researching into his personality is how I got properly interested in Ireland mythology.
I picked up a book or two in my childhood about Irish mythology but The Lord Of The Rings was more interesting, ironic since Tolkien was a huge fan of Irish among other mythologies. Unfortunately that's how things change, the current generation looks back on folklore be paying homage in respect but as a result they change the legends and meanings to fit themselves. It's why I have a respect for religious texts, a large amount of care is put into preserving them, the theologians have to put aside what they wish to be true and focus on what is true.

The painter John Martin whose images I used was known for his depictions of the Apocalypse and rarely painted/engraved anything not related to The Bible. Funny seeing how he was a Deist and defended these claims, you can see how nature* (*the banner of the Romantic Era) causes chaos. Talking about Deists, Voltaire and Thomas Jefferson where admirers of Oisín (son in the title of this poem/song). Voltaire mocking him in parodies and Jefferson saying that Oisín was “the greatest Poet that has ever lived”.

For my interpretation behind the lyrics/poem could have been written much earlier but brought to the mainstream Anglican audience in the epic poem “Fingal” in 1762. At the first half of the 1760's there was a lot of Protestant Anglican scholars who revived the old bardic tales of Ireland. The words “Now there is no region of the city under King Georges flag that is not in darkness and its towns deep in sorrow”, this would defend it being written in this time.
Another plausibility of when it was written is during the Napoleonic era when Wolf Tone (Irish nationalist of 1798 rebellion) allied with Napoleon for French troops to land in Ireland weaken Britain. The important words “To Cork the ships in sorrow” strengthens this. There was an act of nature that saved Britten from losing Ireland under its rule, storms off the coast of Cork in 1796 caused French ships to drown and to be unable to land, it was know as “Expédition d'Irlande”. For more plausibility on this there is a famous painting of Ossian (son of Finn) with French soldiers known as “Ossian Receiving the Ghosts of the Fallen French Heroes” by Anne-Louis Girodet.

In the booklet the only information behind this song/poem only reads...
“Traditional, arranged by Iarla Ó Lionáird, Gavin Bryars and Kieran Lynch. Text and original version from The Journal of the Folk Society, Volume VI Number 23, January 1920, collection by Mr A M Freeman”