Chris Blizzard gives us a run-through of how to go about split toning during your post-processing edit. Split toning is a process of tinting the shadows of an image one color, and the highlights another. It's an incredibly effective technique for adding mood to images, like adding some red into the shadows can have a "vintage" effect.
Concert photography, is littered with red, yellow, blue and green lights, low light and a severe need to improve the quality. Split toning may be the benefit for a vintage effect you want to create. Or even to get that dead skin look, up to par by elevating the white balance.