Something went wrong. The post got moved to the correct section, but no critique!

I'm a newbie, so if I suggest something that goes against what your teacher, or more experienced people say, take what I say with a grain of salt. Also, please forgive me if I explain something you already know. I've always been a believer in too much information is better than too little, and I have no idea what your skill/knowledge level is.)

Main thing I noticed was that your upper arm was moving back and forth a lot. What I've been taught is that the elbow should be locked into place for whatever height the string(s) you're play is at - it shouldn't move back or front at all, ideally. I've also heard that playing at anything but a direct 90 degree angle hurts your sound. (You have different pieces of bow hair hitting the string at different times, which makes the catch-and-release motion less smooth and predictable.)

Related to that, your wrist doesn't move. You're using most of the bow (very good - not a lot of people do that), but not the tip.

What I've been taught is that if you're starting at the frog, the wrist should be cocked down (i.e. towards the inside of your wrist) and the fingers curled, tipping the bow hairs over onto the far side. (Your arm exerts a lot more weight at the frog, so you use less hairs to compensate (and maybe your little finger, too.))

As you move the bow down, the fingers steadily uncurl, and the wrist moves towards straight out.  As the arm moves out towards being as far from the instrument as it can get, the wrist becomes more and more cocked again, but in the opposite direction. At maximum extension (the tip of the bow on the string), the wrist is cocked pretty far back towards the outside of the wrist (the opposite direction from where it is when the bow is at the frog.)

The idea is that the movement of the lower arm describes an arc, with the point at the elbow. You need a straight line, so the wrist and fingers move in coordination with the elbow so produce a straight line as a final result. I'm taking my teacher's word for it that trying to "draw a straight line" with the upper arm moving, too, is a Bad Idea.  (I suspect it adds one more moving part, and the end result is poorer control.)

Your wrist seemed to be pretty much in the central position all the time. That could be not knowing that it's supposed to change all the way up and down, or it could be a symptom of tension.

You keep the non-playing fingers fairly far from the fingerboard, which slows down your fingering speed.

Positives:

You kept your elbow up the entire time, at the proper angle for that string, and it showed. No unintended double notes, no wrong strings.

Your intonation is solid. Don't know how much of that is the tapes and how good the intonation is at root. Try playing it with your eyes closed from time to time to see. (My teacher told me to just learn them by ear. My intonation isn't as good as yours, but it's not too far behind, and I won't have that huge shock when somebody down the road takes my tapes away from me. ) UPDATE: I just watched it again, and it looks like you were reading music, not looking at the tapes, which means your intonation is quite solid.

I couldn't see anything major wrong with your posture. (That might be my inexperience showing, though.) Your left elbow looked like it could have stood to be a little further under the violin, but you didn't seem to be straining at all to hit the notes, and that's what matters. You were obviously far enough under it.

Hopefully, this will spur some of the people who know what they're talking about to speak up, too.    Hope it helps,

Charles