One downside to spotlights is when the background lighting is weaker – which for clubs shows like this is almost always the case. However, to be fair, Franti's crew dialed up the lights a pretty good degree – the last photo above is evidence of that.
The other downside to spotlights is that unless there are spots on everyone, it usually means just the singer and possibly soloists are lit. So when the stage lights do go up on other band members, it's a real race to fire off a shot.
For this show, the Nikon 24-70mm f/2.8 was a fantastic primary lens. The quick-focusing and the range were perfect for Franti's front-of-stage performance.