Obviously, going from an orchestral score to a piano duet score is hard in general. But I am running into some difficulties with transposition. 2 instruments I am transposing are Bb clarinet and A trumpet. Usually, this isn't hard. But I have run into a spot where it differs a lot depending on whether or not it is down a third or down 3 notes on the scale. The Bb clarinet note looks like a D so I know it is C. The A trumpet note looks like a D as well. Usually, I would transpose it to B, down a third. But this leads to a minor second. This isn't so bad in an orchestral texture. But in a piano duet, it is quite noticeable and quite dissonant.
Here is the chord I am going to get if I go with my usual transposition:
As you can see, the bottom 4 notes are a B major chord. But it has a C mixed in with it. This not only makes there be a second interval between the C and the B, but also between the C and the D#(thankfully, these notes are several octaves away so the second won't be noticeably dissonant, the top B though is only 1 octave away so it will be noticeably dissonant), and a tritone between the C and the F#. I think that the tritone will be very noticeably dissonant, even with the F# being 3 octaves away from the C.
If I go with a 3 notes down the scale transposition, the top B becomes an A. Same dissonance level but with different notes(2 seconds and 1 tritone). I don't think I want this level of dissonance in a piano duet. But if I change the top note, it won't go to F# as it is supposed to before the A section starting with the G major chord comes back.
Now what? If changing the transposition of the A trumpet line won't work and I can't change the notes in the Bb clarinet line, how am I going to avoid the mixed major/diminished sound from the tritone with the top note and the major chord? How else can I make it not so dissonant, especially since the chord has 2 seconds along with the tritone? Or will the tritone not be noticeably dissonant with the F# being 3 octaves away from the C and thus I won't get much of a diminished sound?
Here is the score I am transcribing. Measure 22 on page 26 is where I am getting trouble related to dissonance.