Snoop “Snoop Doggy Dogg” Dogg might be the quintessential 21st-century Rap star. On the music side, he was a big part of the legendary Chronic album by Dr. Dre and his first couple of solo releases are almost as classic. But it’s what Snoop has done after his initial musical success that has made him representative of Rap stardom today, making movies (OK, one of them was Soul Plane, but still …), pimping for a number of products in commercials and being a fairly ubiquitous, cartoon-like Pop cultural presence. In an industry struggling to find new ways to sell product and personality without just selling music, Snoop and his smarter peers have always been ahead of the curve. Snoop’s managed a few great singles since his initial heyday and he continues to sell a lot of music, due largely to his business acumen, but also for the attention he puts into his musical projects. Like big-time Hollywood actors Johnny Depp or Brad Pitt, Snoop doesn’t have to lower himself to make a lot of money, instead being able to pick and choose his own next move instead of taking whatever is handed to him. Snoop’s appearance at the Madison Theater Saturday is a part of a handful of recently announced club dates. Somewhat oddly, Indie/Space Rock band The Constellations open the 8 p.m. all-ages show.