Of course I know this movie! It's awesome! And I'd like to point out something: she isn't actually that good at singing. She's not having fun because she's got tons of talent; she's having fun because she's there, doing it.

I love this movie because it talks about something few other movies do: how hard it is to be on the edge of doing something really well... and not really know whether you have what it takes to make it there fully. But at least part of the answer is: you don't have to be dazzlingly good at something for it to still be worth doing.