If it's a binary choice then I think 2-parent households is the answer. Like others have said 2-parent households tend to have a higher income level. There a plenty of "title-1" schools that have "successful" band programs. Now what you define as success is another question.
I've seen posted here before the percentage of free/reduced lunch for each State Marching band. Usually, but not always, the higher the percentage the lower the ranking.