To sing a song is quite different than to write a poem. I'm not and never will be a novelist, but to write a novel is not the same thing as writing a play. There is a difference in form, but essentially what you're after is the same thing.
As a novelist, I suppose I can say that I'm highly articulate. But I know, as a person, in other ways, I'm not always articulate. I think we are all, from time to time, inarticulate, at some level, about some things.