Re: applying to grad school
Emily:
I'll give you my point of view as a professor at a graduate program at a major University, although not a business school, who just went through a stack of applications. We also think work experience is important. But I tend to attach more weight to work experience that is related to the field the student is interested in. If I were reading your application your dancing experience would not influence my decision to admit you unless you could highight those aspects of the job that are relevant to what a "top 10" business school looks for: intellect, leadership, business acumen, etc.
So unless you can write an essay that illustrates how dancing will make you a better businesswomen and hence a stellar business student I would suggest you leave it out.
Re: applying to grad school
When I applied to MBA schools, I used my dancing business plan as a basis for my essay. The plan, supported by four years of financials showed how I devised and implemented, first an accounting system, then a retirement plan, and finally a marketing plan.
I think the essay was reasonably well recieved, I got in to all the MBA programs I applied to.
HTH
Z