|Hello and greetings from the Critique Club!
Crazy colors, very vibrant. This makes the image very eye catching. Great expression, and the focus on the guitar is great. There is flare, but I think it works with the image.
Delving a bit deeper, for being blindly taken, this shot has some pretty nice things going for it compositionally. I like the placement of him and the guitar, but would prefer his hand not cropped off, but that's a minor issue and surely understandable given the not looking aspect of the shot. I particularly like the roof in the backgroud, however. It is a very interesting element and is placed at just the right place behind his head.
The light is harsh, but at the same time, it works as a decent rim light, separating your subject from the background, so I don't find the harshness problematic.
Overall, I think this is a pretty good example of shooting without looking, particularly considering the fact that you nailed the focus and were shooting a moving subject.