Hey mate that's good! Maybe you coulda snuck in a high end lick or two when the vocalist was getting his beer....great rockin sound! I've just seen how many more you have on YT, checkin' em out.....:~)
I realize this is your first time playing this one at a gig so good job pulling it off! and you will probably already change things after seeing this video and get it all worked out after paying it out a few more times but this is my feedback for this performance.
One thing I may suggest are some dynamics during your solo.
If the band dropped volume and intensity while you played the riff as you did and then everyone followed you up as you start to increase volume and broke loose a bit more by improvising more while going up to the higher end of the harp then it would be a great change up to everything, volume level, intensity, higher notes on harp, maybe hold a few notes for a longer time too and create a bit of tension, then when the stops come in and you hit the run back into the original feel of the song it would be like coming back home after a short trip. I know you drop down later in the song but it feels like this spot needs some shift as well, at least to me it does.
I may also suggest that at the point the singer walked off you take a step forward into center stage a bit and hold folks attention. this way it doesn't look like some one missing but that you are now the focus. Of course he may have just walked off cause he needed to at this one gig and it isn't a regular thing but even if he was there you could still step forward and take up some of the physical space as you take up the musical space then fade back when he comes in again.
Last thing is a bit of a band feedback thing and sort of superficial but You guys look good, I mean real good, not overdone but cool. However, did the bass player spill beer all over his fancy shirt right before the gig and only have a T-shirt available? It won't change a thing about your sound but you all have it together with this look and he kind of stuck out to me. You got a cool hat working and the guitarist looks slick and the singer has the perfect I am the lead guy so look at me white jacket. Just a thought.
Hope that helps and would love to see a vid of the next time you perform this letting us know what you intended to change if anything. Could be a helpful excersise for us to see that process if you were willing to do so.
