I personally avoid anything slower than 2.8. I also personally avoid anything without a constant aperture since I tend to shoot in manual mode if the ligting guy doesn't have ADHD (not too often), and of couse I want to use 2.8 if available, so zooming would mess up the exposures if I don't compensate with shutter speed when zooming.

I had a Tamron 28-75/2.8, that was great low budget lens. Sigma has also some offerings, their 24-60/2.8 seems to be rather cheap.

Another answer to your question would be this: Depends. are you shooting in very low or just low light, are you shooting energetic music or blues/jazz for instance...

Thanks for replying Kalle!

I'm hoping to start shooting my husbands' band so ... nothing major ;) He's in a Prog Rock band and the shows are mostly in bar and small clubs so lighting is low and sometimes ... very low LOL!

Thanks for the explanation! I'm learning by looking at the members' sigs for their equipment and the threads so ... every little bit of explanation I can get helps.