These days in the entertainment industry, it is amongst many celebrity’s tactics to become a double or triple threat – to be an actor, singer, and, if they’re capable, a dancer – to essentially (as I would say) take over the world. Many have already managed to do so, making the crossover from either side in equal amounts, and some surprisingly successful in doing so. From many well-known hybrid entertainers to others you never would have guessed, here are a handful of musically-inclined actors and acting-inclined musicians that will give…