Making a melodic line stand out in written score

Question

I'm arranging an orchestral piece for solo piano, and find myself transcribing a passage with a single melodic line in the lower register, which to play on piano should alternate between the left and right hands. In the original score, this is a cello solist, and everything else is pianissimo brass (a repeating pattern; octaves in the upper register is trumpet, fifths in the bottom is trombone/tuba). Here's the current draft:

𝅘𝅥=66, this is a gentle section that no pianist should have trouble performing. My only consideration right now is really selling that independent melodic line (ms. 140 to 148) in this already-busy score. The entire piece is also quite long; so I want to facilitate sight-reading. It should be clear at a glance where the independent melody starts, and where it ends (that triplet in the last measure is no longer part of it).

Options I have considered:

• Making every other note small. It feels like a nuclear option that'd upset the entire alignment of this section, and it would be unclear where it should end.
• Slurring everything together. I would need nested slurs.
• Identifying every source instrument; so notating vc in small block letters every other measure, tpt, tbn+tba for the chords.
• Putting the cello on a third stave in the middle, notating where it should be left hand or right hand. Then I just feel presumptuous xD

Answer 1

As is, it's reasonably clear where the cello melody starts (less so where it ends), but there are some simple changes to you could make to further emphasize it.

1. Reinforce the p marking for the non-melody parts. A p or (p) or sempre p at measure 140 and/or 141 would make absolutely clear the the mf part is the melody.
2. Similarly, a dynamic marking at the triplet in m. 149 (presumably p or mp) would signal that the melodic function of the "cello voice" has concluded.
3. Explicitly marking the beginning and end of the passage (cello) and (end cello) or (ensemble) or such would also make things very clear, with the added benefit that it would suggest a tone quality to the pianist. No need to mark the other parts.

Answer 2

Two things: First, get rid of unnescessary clef changes in the right hand, as these will increase the distance of the melody notes. And second make sure that the stem direction is consequent: Bass goes down, Top goes up and the melody always points towards the middle. Somewhat like this:

Answer 3

Have you considered explicitly keeping the melodic line in one hand (probably the left) and having the hands cross in mm. 143 & 145? This would emphasize the continuity of the repeated brass call-and-response chords as accompaniment as well as the continuity of the cello line. As you note, this movement is rather slow, so it shouldn't require ridiculous gymnastics to get the right hand over and back. You might have to reassign some of the higher trombone/tuba notes to the left hand to avoid collisions, but it's not an insurmountable thing.