For those of you who are admirers of the fiction of Virginia Woolf, you will already know to what I refer by these words--and she was among the leading practitioners of them. If you read Mrs. Dalloway or To the Lighthouse or most particularly Jacob's Room you will experience within the works an oddly disconcerting element, a subtle ambiguity of character and incident. There is about her stream of consciousness a looseness, an almost frightening element of uncertainty, instability, which resolves into a rather gentle, perhaps slightly surreal, serenity. It pervades the works and its ambiguities make the characters themselves rather ambiguous in some ways.
I was thinking about this solid and shifting as I considered how whatever I was feeling, wheresoever my emotional state, I could put on Debussy (and for me, it is only Debussy, not Ravel, not Vaughn-Williams, not Delius, not Holst, not even Satie--Debussy alone) and the entire world seems to shift for a moment in its orbit and is suddenly a better place--better lit, better coordinated, better composed. Debussy captures the serenity of flowing water, the tumble of the stream over a rocky bed, the smell of smoke in autumnal air, all things momentary, evanescent, ephermal, diaphanous--all things that shift in a moment and are gone. Debussy encapsulates them all and contains them so that shifting and solid are together. Those glimpses, those moments, those intuitions, are suddenly tangible--no longer vague and fleeting and gone, but substantial, permanent, perennial. The moments of the opening of a blossom are suspended, it is forever opening--not a loop, but a continuity that never reaches an end. In this way, for me, Debussy capture eternity--time vanishes while I listen to his music and I am caught up in the flow of the eternal where all that happens happens not in a moment but in a continuity that never ends. The blossom never stops opening even though at some point the flower is full-blown.
And if that isn't vague enough for you, just post a comment and I'll see if I can make it even more vague.
Later: Although on reconsideration, there are parts of Daphnis and Chloe that approach the power of Debussy to bridge the shifting and the solid.
No, no reconsideration. You were right the first time.
Ravel is wonderful. But he's an etching, sometimes in black-and-white, sometimes in color. He's classical lines and pure colors and sparkling lines for instruments that are easy to play. Ravel is a French Nationalist Romantic, with a fondness for the exotic and the antique. He starts with Liszt and the Russians and presses them through his own marvellous filter.
Debussy is more than wonderful. He can be boring. He can be annoying. But he is Great--a Great Master with a capital "G" and a capital "M". Debussy is something New. Prelude to the Afternoon of a Faun changed the world. Listen to the first few minutes of it and then listen to the first few minutes of Daphnis and you'll see what I mean. It's sound, just sound, harmonies as COLOR, fistfuls of notes scattered here and there, not such fun for an orchestra at all. Ravel is melodies, antique and stylized and full of color. With Debussy, music woke up and found that it had left its moorings behind and was sailing on a strange new ocean where the stars in the night sky were strange.
And Debussy's piano is a piano without hammers. "Play the piano as if it has no hammers; reach your fingers into the strings and pull out the sound." A completely reimagined sound, nothing like the fabulous virtuoso concision of Ravel. Even at his most "impressionist" as in Jeux d'Eaux, Ravel is a Romantic Neo-Classical and his harmonies are all adaptations of the norm. But Debussy's fingers are doing entirely different things, starting from scratch, pulling the strangest things out of the soundboard.
There is a case to be made that Debussy stands with the greatest composers who ever lived. There is no such case for Ravel although everything he wrote is touched with his own wonderful magic.
And if they stand for anything in the music of their time, they stand for opposite things. Stylized past and present vs. the Abyss.