Thanks Michael. Good advice.

Many thanks to everyone for your advice/input. Although I'm not too yourg in years I am a young photographer. Hopefully I can pull a couple decent shots out of this venue.

Thanks wotsmith.

Thanks agAin SS. Good capture with such harsh lighting.

Thanks James56. Nice shots.

Thanks Didereaux. Hope to have a blast.

Thanks jcboy3. Good captures.

Thanks OldTimer.

Thanks twowindsbear. Will do.

Thanks RichardTaylor.

Thanks SS. This is a contemporary Christian concert. Usually there is some movement but not too fast. However in recent concerts other bands tend to use lots of bright, multicolored LED lighting (from various spots to full screen LED video behind band). While the lighting looks good it can change very fast in color and intensity. Singers and band usually have lots of harsh lighting behind them.

I have been asked to take pics at a live concert of a well known artist at an area college tomorrow night. I will be given a photographer's pass and can capture anything I wish. The sponsors would only like to have a few photos for their website. Since I've never had this opportunity, nor do I have any experience working with such diverse lighting schemes that change so rapidly, I would Appreciate some input/advice from you guys. Thanks in advance for any and all comments. My equipment is as follows:
Canon 7D
Canon XSi
18-55mm kit lens
Tamron 28-75mm f/2.8
Canon 70-200mm s/2.8 IS STI II
SIGMA 50mm f/1.4
Canon 430ESII FLASH
CPL & Neutral Density filters for the 18-55, 28-75, and 70-200 lenses

First, thank you for the outpouring of input to help me in making a very important lens decision. I have been very pleased with my Tamron 28-75 and my Canon 70-200 (wow-what a beast). I think researching something in the 17-70mm or 15-85mm range would a good fit for me. In reading each post in this topic I realize that you guys have given me an enormous amount of needed information that I will not take lightly. I'm humbled. I will do my due diligence and let you know which lens I decide to purchase. Thanks again and may the Lord bless you abundantly.

Thanks for all the input guys. You've provided me with plenty of info to ponder. Seems I may lighten my gear bag a bit for better quality all-around toys. The image quality of the L lens has given me GAS. :shock:

...thus the dilemma. The image quality of my Canon L lens is better than the image quality of the Tamron. The Tamron 2.8 gets me shots that otherwise I couldn't get. However the Canon 24-105 f/4 L would give me better image quality but probably would not get some of the shots I'm accustomed to capturing indoors or just after sunset with the Tamron 2.8. Sounds like it's going to cost a few bucks more bucks than I anticipated.