Who’s the most powerful woman in media and entertainment? It’s not the head of a TV network or a movie studio — it’s Taylor Swift.That’s according to Forbes, which has published its annual list of The World’s 100 Most Powerful Women, based on four main metrics: money, media, impact and spheres of influence. Taylor comes in at #21 on the list, which makes her the highest-ranked, and therefore the most powerful, woman in the Media & Entertainment category.