I’m studying Mozart’s late symphonies and piano concertos these days and thinking about what makes his music extraordinary.
Of course, there are many aspects – taste, harmonic sophistication, lyricism, humor, a sense of inevitability peppered with surprises, and so on.
The incredible variety in his orchestration got me thinking about the possibilities for sub-ensembles within the classical orchestra:
I’ve made a PDF (see below) that lists all of these possibilities within the classical (Mozart, Haydn, Beethoven, etc.) orchestra; it’s helped spark my imagination, and also as a prompt for inner-ear “visualization” exercises.
Take a look at the lists and imagine (hear in your head) what music made from these groups would sound like – its density, timbre, etc.
The Greek composer Vangelis said in a 2008 interview that the classical orchestra was the first synthesizer. Mozart, particularly in the later symphonies (after #25) and piano concertos (starting with #17), uses a great number of the possible instrumental combinations, mixing colors with gradient, chiaroscuro, transparency, and opacity, across the full sound spectrum.
I’ve used parentheses to indicate the possibility of employing solo instruments or divisi within sections; take these into account and the true number of instrumental combinations becomes astronomical.