The text to Purcell’s Ode to St. Cecilia was written by Nicholas Brady. He goes through various instruments, dealing with the organ thus:
With that sublime Celestial Lay
Can any Earthly Sounds compare?
If any Earthly Music dare,
The noble Organ may.
From Heav’n its wondrous Notes were giv’n,
(Cecilia oft convers’d with Heaven,)
Some Angel of the Sacred Choire
Did with his Breath the Pipes inspire;
And of their Notes above the just Resemblance gave,
Brisk without Lightness, without Dulness Grave.
The poet here makes the old apology for the organ: it is the closest earthly approximation to music of the spheres. Emma Kirkby likes to talk about polyphonic music in just this way. Angels (like the angel that “did with his breath the pipes inspire”) have no lungs, are unchanging, incorporeal. The Medieval model associates all of these qualities to the spheres. That music needs no lungs, no breaths, but is everlasting and continuous. This is the reason polyphonic music was the music of the church, according to Kirkby, because of the impression it gives of that unchanging, continuous, celestial sound, just the sort of music that a church service needs. This is also the apology that many, including Brady, make for the organ. Its sound is continuous, and it produces a “just Resemblance” to the heavenly music.
And what exact sound do the organ and heavenly music have in common? They are both “Brisk without Lightness, without Dulness Grave.” To me, that’s just a fascinating description of the organ. We think of dullness always accompanying gravity and lightness always accompanying briskness. But the organ’s music has the solemnity without losing the joy, and the joy without gaining the triviality. Thanks (or no thanks) to 19th century French composers, those categories for the organ have almost been destroyed. Selling the organ to modern churches is going to mean reinventing this sort of connotation when the word “organ” is heard. “Brisk without Lightness, without Dulness Grave.”