I can think of a lot of rappers who have experience shooting in clubs/bars/discos. 😀
LOL!!
😀 That's a good one!
To the OP:
I'd say for the club scene, use a fairly high ISO, because slightly gritty results can be acceptable as long as they're sharp at the point of interest. Better grainy/noisy and sharp than smooth and blurry... For the bands, make sure to meter on the performers, not the lights or overall scene. Then, with that meter setting you can take wider shots of the "big picture" and not have these white spots where the band was..
😉 See if the exposure settings for the performers fall within a similar range, then set manually and shoot away, focusing on composition, not metering. For the crowd scenes, make yourself a reflector you can attach to your flash head (point flash up.) I used heavy notecard stock, and cut several out and kept them in my bag with two rubber bands around my flash at all times for quick use. Experiment with slower shutter speeds and rear-curtain flash synch for some neat effects, especially if there is dancing or a lot of movement. Play around with reduced flash power, up to a -1 stop. Don't worry, not everything will turn out but if you play with it, you'll be rewarded with some unexpected and interesting results. Fast lenses help, but just know your limitations, and push right up to them.
Here's a shot of a performance on stage under lights where I metered on the part of the shot I wanted (face,) with max ISO 1600, and there was plenty of light to hand hold (note: this shot was posted once several months ago in reference to a question about the Nikkor 55-200 lens.)
Model: NIKON D50
ISO: 1600
Exposure: 1/320 sec
Aperture: f/5.0
Focal Length: 130mm w/Nikkor 55-200 non-VR
A club will be darker, but you'll be closer where you can probably get away with 1/60-1/125th sec on a wider lens as long as you synch with when the performer(s) are not jumping around too much. Don't forget those moments between songs when the lead singer is introducing his band, and all the behind the scene stuff that doesn't move (sound guy, amps, audience members who are stationary.) Bottom line: Have fun!!
🙂 (and don't flash the band...
😉 )