The first image I just desaturated and added a slight posterize effect to the image. I also turned up the contrast a little and darkened the image. I think it really brings out the image nicely.
The next image I desaturated and posterized to a much greater degree. You can not get a great view unless you click on the image to see a larger version. It wiped out the background much better and gave a very dramatic look to the image. The strong contrast really brings the face out nicely.
I pushed the posterization even further with this image but edited out the guitar to not be affected. It really brings the guitar to the foreground. I think that it might have been better if the guitar was still colored but it works well.
I only desaturated this image. I choose to select the band members to not be desaturated to make them much more dominant. I do not think I am happy with the result. I think a triptych of this image with each member independently being the only part with saturation might be interesting but right now they all stand out. This would be fine but they take up to much of the image which diminishes the effect.