[gafftaper]

Having done too much work in a room with a 12 foot ceiling, I suggest you do some good scale drawings and pay attention to photometrics. If you've got a 12' ceiling and say a 2' platform. You only have 10 feet of vertical space. You jack the truss up to the ceiling and then you have instruments hanging down from that, cutting the relative height of the instruments to the stage down to around 8'-9'. That's not a lot of fun. Musicians tend to not like lighting instruments hanging 2' from their heads. You need REALLY wide angle instruments. I'm assuming you have some sort of front light truss as well... these will be right at eye level with your musicians so they are going to complain about not being able to see the audience. Try to do truss off to the sides so that you can get some interesting cross lighting angles. Light from the truss in the back pointing forward is going to be either straight in the face of the audience or at too steep of an angle to be useful in lighting the band.

Not to be a downer... there is still a lot of fun to be had. Just do your design homework or you may find it's much harder to light the stage than you expected.