I am writing this piece for a piano flute duet to represent Spring and it has 3 main sections. Those sections are:
A - Quiet, Molto adagio, A minor, very melodic, rocking fifths in the bass, melody rises out of the first octave - Warming up
B - Fortissimo, Presto, still in A minor, more motivic towards the beginning and more melodic towards the end, octaves in the bass - Rainstorm with the sun peaking through the clouds towards the end of the storm
C - Forte, Allegro, Picardy third to A major, joyful, melodic, Alberti bass in the bass, towards the end of the piece it becomes chords
There is a bridging A section between the B and C sections, this one being faster and hinting at the major tonality of the ending while still being in A minor. There is also a transition from the A section to the B section, where an accelerando and creschendo takes place.
You see, I am a bit worried that I might have written part of the Presto section too low for a flutist to play it fortissimo because the lowest note in the Presto is D in the second octave. If I have, I can just raise that part up an octave in the flute with no issues. Nope, not even the issue of going too high and having to switch to a piccolo. I can imagine that on a woodwind instrument, just how low or how high you can play at a certain dynamic has to do partly with the tempo(I know that on the piano, playing pianissimo at a Presto tempo is much more difficult than playing fortissimo at the same tempo).
But, is D in the second octave too low for a flutist to play fortissimo in a section that is at a Presto tempo? Or will everything be okay having D in the second octave being my lowest fortissimo note on the flute because it is a duet and not a whole orchestra? I'm just worried that the pianist might drown out the flute. The section I am most concerned about is Bars 46 and 47, where the flute plays a scalar motive to represent the wind of the storm and it is playing over an implied D minor harmony(I say implied, because the only notes in the left hand in that section are D's in octaves).
Here is the section in question where that D occurs:
For context of where this passage occurs, here is the start of the Presto section:
So, is the D in my passage too low for the flutist to be able to play it fortissimo? Are the octaves in the left hand of the piano going to drown out the flute? Or will everything be fine the way I have it written? The only reason you don't see slurs in the images is because I haven't finished writing the piece yet.