The appropriate implementation of sound has bugger all to do with "morals," and even less to do with genre; it's all about what works in the setting, and it's got nothing to do with the format you use either. I suggest you make your game, try putting some music to it, and see what works; it's a peculiar approach, I know, but you'll learn more and get better results from it than you will by posing poorly-worded questions (yeah, you probably should use audio sound, it's preferable to the inaudible type, y'know?) to an internet forum without showing the people you're asking for advice any context. The sound, ideally, should complement the graphical style, the setting and storyline, and the nature of the action; all you've told us is that the project is 2D, top-down, and of a "similar" feel to some older RPGs (but you've not said how, which is vital) - none of which has any bearing whatsoever on the music.
Just make a whole bunch of stuff and see what works, and try to phrase your queries better if you want better results.
