The Sing-Off concludes its third and first full season tonight, as either the Dartmouth Aires, Pentatonix, or Urban Method will win the a cappella singing competition. But moving the show to the fall as a placeholder for The Voice may have been a mistake. Perhaps unsurprisingly, ratings are down significantly: they’ve have dropped more than a third since it was expanded into a full-season series instead of a two-week special event series that aired during the holidays, when few networks air original series. This fall, it faced off against Dancing with the Stars, among other shows. That ratings decline, and the previous success of the two-week December version, prompts Media Life to say that “It’s hard to imagine that Sing will return as a regular series, though NBC could revive it next December as a limited-run special again,” because it “is averaging a 1.6 18-49 rating, a distant fourth among the Big Four networks in its timeslot and often ranking even behind Univision.” View the ...