The musical numbers, instead of having a disrupting effect and stopping the flow of the story, actually advance the plot because they’re integral to the story and this particular type of penguin.
Emperor Penguins apparently find their mates by singing.
While it all sounds the same to us, they are highly attuned to each others songs.
The film cleverly translates that idea to the screen by having these animated penguins sing iconic pop/rock songs.
The animation is top notch and the style perfectly suited for the story.
This isn’t the goofy cartoonish animation seen in this past year’s other animal-oriented films.
It’s very rich and leaning heavily towards realism.
The vast icy landscapes seem to be copied straight from documentary footage.
In the cold land of Antarctica, the Emperor Penguins each express their true love with a special heartsong of their own that expresses their very being.
However, the misfit Mumble cannot sing, but instead has an extraordinary talent to tap dance with almost magical energy and expression.
Nevertheless, the deeply conformist leadership of the colony fearfully blames the young penguin’s unorthodox ways for the lean fishing that threatens them all.
nice 
magic