For my fellow non-watchers of the Grammys, a lyrical challenge

See if you can tell me who originally penned this song without resorting to Google. Okay, you can use it, but only if you get stuck.

I am the wind that breathes on the sea
I am the wave, wave on the ocean
I am the ray, the eye of the sun
I am a tomb, cold in the darkness
I am star, the tear of the sun
I am a wonder, a wonder in flower
I am the spear as it cries out for blood
The word of great power
I am the depths of a great pool
I am the song of the blackbird
Who but I can cast light
Upon the meeting of the mountains?
Who but I will cry aloud
The changes in the moon?
Who but I can find the place
Where hides away the sun?
Ailiu Iath Nerenn
Ailiu Iath Nerenn
Ailiu Iath Nerenn

From the breeze on the mountain
To the lake of deep blue
From the waterfall down to the sea
Never changing or ending
On the voice of the wind
Sing the dark song of Erenn to me