Yes, that is a flash on the top of the camera, being held about a foot from the singer's face.
Shooting live performance presents unique challenges. This is one area where a photographer's equipment is essential
for quality output. Lenses, and in the case of digital, the camera itself, can make or break even the best photographer's work.
Recently I was asked to shoot a show and there were a number of other photographers, and a few
people-with-cameras there. There is a huge difference. I have attended, and photographed, shows where doing this to a musician
would end very unpleasantly. That "technique"
also creates rather unpleasant shadows and extremely harsh light.
The end result of using a flash at close range during a show.
(That's someone else's flash.)
In many cases, such as dance and for musicians on raised stages, using a flash can be downright dangerous for the performers. Not being able to see
the edge of the stage or other performers can be disasterous in the form of falls or collisions. In the case of the "rowdier" shows, musicians need to be alert for people or other objects that may suddenly appear on stage with them. Being blinded by a flash is not an option.
Just like in sports photography, my job as a professional is to capture the performance without interfering in any way with the people performing.