I echo what has been said about the tree.
It is a really nice tree. I notice 4 limbs on the tree, and there are 4 band members. Maybe have them pose as the limbs? haha, sounds corny, but could be pretty fun!
The split up group shot is pretty nice. However, the lower right guy needs a different expression. Some of the exposures are a bit off in that some faces are really white/bright/blown out, but I do like the concept.
Another concept with this type of picture would be to have the 4 guys kneel down at the 4 sides of the tree, and then shoot them individually. A split group shot like this could look like it was rotating around to show each of them.
The individual shots are ok as well.
Its ok to cut part of the hair off, but in some of them I feel its a bit too much. The last one has most of his forehead cut and Robbo has a weird hair line thing going on.
While I like the idea of the posing and the pictures, if you are showing this as a group set, you should make sure that everyone fills the frame in the same way and that the exposure is consistent between them. Else, you may be making one member looking more like the band leader.
Make sure you fill the frame with your subject. All four individual shots are ok, but I find there is too much of the background / other things going on that it diverts my attention from your main subject
Nice job overall though