Here's a String Quartet.

String Quartet in D Minor-1 Free Sheet Music by Robert C. Fox for Various Instruments | Noteflight

String Quartet In D Minor-2 Free Sheet Music by Robert C Fox for Various Instruments | Noteflight

String Quartet In D Minor-3 Free Sheet Music by Robert C Fox for Various Instruments | Noteflight

String Quartet In D Minor-4 Free Sheet Music by Robert C. Fox for Various Instruments | Noteflight

Wrote five, but this one is closest to a true string quartet.  2009.

Hi Churchcantor, or Robert, however you prefer 😁. It seems that this post went through in silence. Let's fix that.

I listened to the first movement. While I enjoy the repetition of some ryhtmic patterns, I think it's too contrasting in terms of material (or it appears so at first) and not very well-founded structurally. At the same time it sounds plain: not a single dynamic marking (maybe I missed some?), almost constant tutti except from some sections where all in a sudden virtuoso-fast passages appear and also a pizz. ending that does not convince me at all. But I just could be wrong, I listened to it twice and more often than not pieces require a bit more to be appreciated, specially if they're ones like you submitted. Some other times I just don't like them, though. It's perhaps harmonically daring or inconsistent in that regard too: a more in-depth analysis would reveal one or the other, or both, since practically everything is valid this days and I'm sure you could justify many of the things I may have heard as "wrong" or "weird" or "misplaced", etc. At the end of the day, almost all that matters is that you yourself feel that the work is decent enough. Several years have passed since 2009 so if you are not fully convinced now, maybe these points I brought here are worth noting (and maybe at this point, you know the majority):

• Even if you didn't change a note, a better balance of the dynamics of each instrument would greatly help.
• The sudden contrasting sections do not reinforce the stability/coherence of the movement, in my humble opinion they rather weaken it. M17 & M18 appearing in the middle of the syncopated section, so dense and all on a sudden, is one example of such a contrasting section. In my opinion, even if you want an abrupt transition, I think it could be stated better (again via dynamics, but also via articulation or even slight rhythm changes, there are many ways to accomplish this better) both in the "before" measures and in the "after" measures. 
• I can see the movement can be technically demanding at times too. Quadruple stops... Assuming these ones in the score are doable specifically, are you completely sure you need them to be quadruple? After all, it's not a solo, maybe you can distribute the voices in order to avoid these maybe problematic stops. 

I won't comment much on the score per se, since I am well aware of the poor layout results noteflight default usually delivers. Not to mention the default midi sounds it uses. Wish you could upload a better audio here, it would be neat... I'm myself not a fan of it, but perhaps porting your sheet music to Musescore 4 is not a bad idea.

It's 7 AM here and I really need to sleep, but I am eager to listen to the rest of your work...! Thank you for submitting it here and once again, I am sorry the post got a bit lost. Usually posts with material to be analysed are replied sooner or later...

Kind regards,
Daniel.

Cool!  Actually, had forgotten for a while that I posted this thread and did repost the quartet in a thread that got some views...in 38 years, and about five attempts, my closest thing to a string quartet!  The bowings, dynamics, and expression markings are in the paper manuscript.  This was written in a garage smoking a pipe, with a cd box set of Mozart quartets and the score at hand.  

I can see why some might not like the sudden transitions, but I guess I just wanted that first movement to be peripatetic.  The work could be considered overscored!  I'm not revising it 16 years later.  I don't mind if the quad chords are rolled and rough!

Posted in the other thread for this piece:  

I have a kind of personal "program" for the first and second movements, that I came up with long after the quartet was written!  The first movement is a conversation between me and Dmitri Shostakovich, with Beethoven and Brahms politely listening, and Antonin Dvorak keeps bursting in the door drunk, whistling his latest theme!

The second movement, Courante and Fugue, is even funnier:  the Courante sounds to me like the barrel organ is out of tune at the carnival, and the fugue sounds as if Beethoven, whilst sketching out a fugal section in his late quartets, was even drunker than usual... 

Movement 1

Another Stravinsky styled piece... Anyways, my favourite part was bar 11 to 30. The rhythm sometimes is random, but feels like poco accelerando. I saw a cadenza at bar 37 and 45 to 46. I like the chromatic feel. As Omicron said, you have a lack of dynamics and not enough moments that are not tutti. You should add more of these. In contrast with Omicron, I believe the ending made perfect sense. It is also late, here, so I will continue later. Please be patient.