From Brent Warner of the Greater Washington D.C. Area Manx Society comes this gem.
There’s a piano piece by the American composer Henry Cowell, “The Tides of Manaunaun”, using the Irish spelling of Mananan’s name, but it’s the same guy.
It sounds very mystical, as intended. Here is the composer’s description:
In Irish mythology, Manaunaun was the god of motion and of the waves of the sea. And according to the mythology, at the time when the universe was being built, Manaunaun swayed all of the materials out of which the universe was being built with fine particles which were distributed everywhere through cosmos. And he kept these moving in rhythmical tides so that they should remain fresh when the time came for their use in the building of the universe.