Craig F commented on the post about questions in a query
I think that starting a query with a question would work better with an elementary or mid-grade book. I am stealing from one of my favorite vommenters, but here goes. What is that sound from the fields? It's Clara, the singing cow. Her song can pull the moon down from the sky.
I want to underscore the point that the question shouldn't be yes/no.
What is that sound from the fields isn't a yes/no question.
Who killed Roger Ackroyd isn't a yes/no question.
Both Craig's example and Dame Agatha Christie's seminal book are examples of a question that DOES work; it engages your reader's interest.