We are singing this again! after the Asperges but before the Introit.

Is this not rather like a certain song which states "I heard there was a sacred chord that David played and it pleased the Lord"? It furthers a legend, but does not yet provide evidence that King David invented such a chord, or tell us what that chord was.

"I heard there was a sacred chord that David played and it pleased the Lord"

Seated one day at the organ,
I was weary and ill at ease,
And my fingers wandered idly
Over the noisy keys.

I know not what I was playing,
Or what I was dreaming then;
But I struck one chord of music,
Like the sound of a great Amen.

It flooded the crimson twilight,
Like the close of an angel's psalm,
And it lay on my fevered spirit
With a touch of infinite calm.

It quieted pain and sorrow,
Like love overcoming strife;
It seemed the harmonious echo
From our discordant life.

It linked all perplexèd meanings
Into one perfect peace,
And trembled away into silence
As if it were loth to cease.

I have sought, but I seek it vainly,
That one lost chord divine,
Which came from the soul of the organ,
And entered into mine.

It may be that death's bright angel
Will speak in that chord again,
It may be that only in Heav'n
I shall hear that grand Amen.

@StimsonInRehab

I am sure I have seen this in the Analecta Hymnica...Vol 49 pg 26, although we have 3 to choose from, and for the Octave day we have another but do you have the music?

@Andrew_Malton
We will be singing it in a Parish Church on Sunday!

Here's a score.