And so-- The Wrinkled Crown, by Anne Nesbet (HarperCollins, November 2015).
Linnet's story starts up in the Wrinkled Hills, where the twisty landscape holds magic, and where girls aren't allowed to play, or even touch, the stringed instrument known as the lorka before they turn 12 because if they do, they will be taken off by the magic to Away. Linnet knew this perfectly well, but it didn't stop her from making one for herself- her wanting was to great for caution to hold her back. But the magic twists itself, and instead of Linnet being taken, her best friend's spirit is instead. Her fading body is all that's left.
Linny's mother came from the city down below the Wrinkled Hills, where the twistiness of magical foldedness met the straight and level Plains that could be surveyed and measured nicely. She thinks it's possible that the sister she left behind when she adventured into the hills might have a remedy that will bring Linny's friend back. So down out of the hills Linny goes...accompanied by Elias, her father's apprentice in lorka making (whom Linny doesn't much care for, since he got to learn instrument making above board and with encouragement, and she didn't.)
There in the city divided between magic and science Linny finds herself greeted as if she stepped out of a legend. And, while narrowly avoiding being used by a whole score of people with different ideas of how a living legend might be useful, she actually does what the Legendary "Girl with a Lourka" was supposed to do...
But being a Chosen One of Destiny was not why Linny came to the city in the first place, so she continues to search for her aunt, who is out even further from the magical hills of her home. And there are fresh dangers and excitements, and there's the whole question of whether a "cure" for magic is a good thing or not, but it's clear that it's a really good thing in the end that Elias came too, and it is also a really, really good thing that Linny has been adopted by a most extraordinary cat (a great cat, both sciency and magicy!) and in any event that's the gist of it.
So this is an interesting story of magic vs. science, but the "vs." part isn't there in Linny's mind because she can appreciate both, so it's also a story of appreciating different perspectives on reality. And it's about factions trying to use legend to gain power. It's not tremendously subtle political intrigue, and so that part of the book on its own isn't quite quite strong enough to make me throw the book eagerly in the direction of grownups who like MG fantasy (although it's pretty much just right for ten-year-olds). But mostly the book is about a brave girl with very interesting magical and musical gifts (and a very interesting cat friend!) being clever and determined, and this I enjoyed very much, and so I happily can recommend The Wrinkled Crown very nicely indeed to both the target audience and to grown-ups who like the same sort of MG fantasy as I do.
(final thought--my 12 year old son is aging out of MG and is reading YA now. Which I guess was bound to happen. But I would have given him this one in a second two years ago, and now am not sure that it would grab him...which makes me a bit wistful.)
(second final thought--I always appreciate girls who take delight in sewing and make it something magical, because I rather like embroidery and get cross when we don't let girls do it anymore because they have to be off climbing trees or doing other "boy" stuff. So I really liked that Linny's friend who gets magiced away is an extraordinary embroiderer, and that one thing she sewed is absolutely lovely and magical and also a very useful thing for Linny to have taken down to the non-magic world).