Viola/guitar Composition

Hi there, 

I am composing a duet for viola and guitar, and have some queries regarding voicing possiblities etc, as well as virtuosity in passages. 

It can be notated as I have it, or it could be notated in semiquavers, the bpm is 175 for a crotchet. 

Here is a link to the score on youtube. 

Tnks in advance for any advice etc. 

https://www.youtube.com/watch?v=oupfeUaWDpo

I can't really see all the notes well... it comes out a little small on YouTube. I would suggest uploading the score here. At first glance the guitar part seems perfectly doable, but like I said; I would need to be able to see the notes completely, especially for the chords because that's where composers unfamiliar with the guitar fail to understand its chordal possibilities. As for the Viola part, the single lines look doable; I would need a more visible version of the score to confirm the double stops. 

A global point about triple stops: it's not possible to sustain them like that.  Your performer (unless you instruct him or her otherwise) will arpeggiate and then sustain the top two notes or just the top note (usually top two if it's easily possible in context, as with yours). 

Double stops are easily sustainable but not for very long (the player will need to change bow directions so there will be a very audible stop in the sustain - consider notating where they should change bow direction). 

Can you meet with a violin or viola playing friend and try out some of these things?