Well, don't take it the worng way but this piece isn't really good, either in orchestration or in the whole composition, the chords sounds really wrong to me, would be fine to get an analysis from you, why you come in that chords and why you used it. The MP3 File sounds MIDI, thats a big negativ point to. Let the Strings live, let the Piano live and not so strong and accurated performence.
in short words, i think you'll need to study musictheory before writing for small or big ensembles to get an feeling for the musicans and a feeling for writing good music. It sounds here (i know thats really hard) that you used that notes you just found on your keyboard and they are just won't work. Thats my ciritc, but don't take it the wrong way, thats how i felt when hearing, i switched off after 2min cause it bored me.
best wishes for future,
F