I don't know if I can choose "the greatest" chilean of all times, but defininitely I think she is one of the most important woman of our country. She is Violeta Parra.
She is a popular and folcloric singer of the 60's, but also she was a very recognized artist. Besides as a composer, she was painter, sculptor, embroiderer and ceramist. So, she is a very important figure of the national culture, her musical and artistic work it'

If she was alive I don't know if I would ask her something in specific; actually I think that she must was that kind of person that have a lot to say and only need to be listened by other people... So I think her best voice is the one that arise in her songs and pieces of art. In that sense, I would ask her if I would hear her sing, it would be a pleasure.