
X (especially if any of my suggested revisions make sense to you)
See my version (below). It seems to me the star of this drawing is that gaping hollow. Yours is too sharp-edged and reads very flat as a result. I’ve tried to soften those edges (based on memory of similar things I’ve seen), but even so the interior of that space needs more volume (it will have to do with the modeling). It has farther to go, but this is the direction I recommend.
I’ve darkened the negative space to the right of the trunk to highlight the light along its edge (and throw the hollow into greater relief). I’ve also softened and lightened the opening in the tree in the background which was competing for attention–especially since the edge of its hollow was much too sharp and graphic. I don’t see this as a duet, as your title implies, but a soloist with a back-up singer. Just as darker notes and advance and lighter ones recede, sharper edges advance and softer ones recede.
I also darkened the shadow side of the foreground tree and started to let that shadow overtake the hollow, to pull it around to that side of the tree. Then I added vaguely grass-like hatching to the shadow rather than the more generic diagonal hatching.
I often liken the second half (or last quarter) of a drawing to what a conductor does–the music has been written and the players know their parts, but it’s up to the conductor to “mix” the sound, to bring up this and subdue that in order to capture the essence of the whole–the same thing that recording engineers do with the parts in recorded music.
The best way to develop an eye for this, besides experience, is emulating how others have done it–today’s recommendation is Seurat—
I went looking for a Seurat drawing like this one to demonstrate simultaneous contrast–the way adjoining values exaggerate one another a bit, and how he likes to play this up, subtly but definitively, but…
…I came across this one, below, which is such a great example of what you’re doing in terms of balancing and integrating foreground and background (ultimately dissolving into the paper), establishing focal points and hierarchies of value. Even his touch–note how he draws the shadow of the tree to evoke a grass texture without resorting to cartoon-like blades of grass. A great drawing for you to study (and once again, your answers seem to be found c. 1890-1910).
Just as an aside (less relevant) you might also enjoy the work of my friend Bill Richards, who gets a very silvery light out of his low-contrast graphite drawings:
But your drawing of the hollow also brings to mind O’Keeffe–
Love the way she keeps one foot firmly planted in the natural world but allows the other one to amplify, refine, and distill the elements of the image–contrast, hard and soft edges, etc.–to greater effect.
In short, that’s what this drawing needs–a more confident and authorial “conductor” to push the image further (an ability you certainly have if this drawing is any indication):