Is that Constantin Floros-New Ears for New Music? With "labels" I mean styles, like newcomplexity for Ferneyhough or spectral music for Grisey. You have anyway made it easy for me! No need to surf this whole thread...
Well, I listen primarily to 21st (and late 20th) century music and I can tell you it's really
really hard to come up with unifying labels for different groups of composers.
We can be descriptive in how we compare composers with others in terms of things they share in common......Mark Andre and Claus-Steffen Mahnkopf have written a number of slow, sparse compositions with very airy or still sounds interrupted with bursts of colour or sudden contrasts. Mahnkopf, again, has some similarities with Haas, Coates and Catherine Lamb in their use of micro-intervals (Bernhard Lang's Monadologie XII
The Saucy Maid is a significant example of microtonal music on a massive scale: two orchestras tuned a quartertone apart!).
Dench and Finnissy have composed some of the most substantial additions to 'new complex' piano repertoire but their music is so distinct from one another that it's hard for me to even use the same label to describe them.
Composers like Moritz Eggert, Olga Neuwirth and Wolfgang Mitterer have made use of post-Schnittke polystylist techniques each in their own way, with their own sound. Mitterer is particularly fascinating in that he has worked extensively with electronics as well, and there are many other composers whose works featuring live electronics with acoustic instruments are particularly exciting and all unique (Clemens Gadenstätter's
Comic Sense is a personal favourite). But then again Panayiotis Kokoras is creating incredible works for solo instruments and fixed-media electronics that seem to want to exist in a category all on their own.
Helmuth Lachenmann is so difficult to categorise, but he has had such an enormous influence on the way people think about sound, music, tradition (Wolfgang Rihm as a traditionalist/modernist as well!) and innovation in the 21st century, especially when it comes to instrumental technique, including all I have mentioned above (and below). Czernowin and Liza Lim have a comparable exploratory approach to instrumentation, but both of their styles are uniquely melodic (so is Mahnkopf's, in his own way) and in contrast to other composers with an interest in colour but whose music tend to be far less lyrical (like Adámek, Steen-Andersen and usually Bernhard Lang.)
I could keep going, actually I don't really know where to stop, but I will probably just end this post saying that I honestly do not know how to label and categorise these composers or why it would be much of an achievement to.........
I don't know how to label composers like Ulrich Krieger, Elena Rykova, Rupert Huber, Rebecca Saunders, Bernhard Gander, Nikolaus Brass, Natasha Barrett, Richard Barrett, Atli Ingólfsson, Adriana Hölszky, Joanna Wozny, Wenchen Qin, Elena Mendoza, Dai Fujikura, Clara Iannotta, Saed Haddad, Jason Eckardt, Lisa Streich, Marianna Liik, Matthias Pintscher, Aaron Cassidy, Misato Mochizuki, Keeril Makan, Peter Ruzicka, Salvatore Sciarrino, Ramon Lazkano, Lucia Ronchetti, Unsuk Chin, Édith Canat de Chizy, Andreas Pfügler, Isabel Mundry, Alberto Posadas, Johannes Schöllhorn, Johannes Maria Staud, Johannes Kalitzke, Beat Furrer, Ruben Seroussi, Peter Jakober, Rupert Huber, Wolfgang von Schweinitz, Milica Djordjevic or Anthony Pateras and I'm not sure exactly why I would want to come up with any definitive label.
Making comparisons is the best I can do for you, I'm afraid.
Music After the Fall is still probably the best book you can find as well, unless you have access to some musicological journals on New Music.
