Let me pretend for a moment I am having a conversation with someone, so that I can employ dialogue for the sake of showing you how I’d use it in a scenario where it might be occasioned. For instance, I am writing just now in Manhattan, in the atrium of a building where there are small tables and chairs at which the public can sit and drink coffee, or do work, and listen to music that is being played at a piano by a person who I think must be a professional, or at least professionally trained. The piano is next to the escalators, which go up to the mezzanine and down to the subway. The person who is playing is very good, though no one seems to be noticing him, or paying him any mind. Which itself might be evidence of his proficiency, I suppose. Insofar as an unskilled player would draw attention to himself.