I'm well-acquainted with the local wisdom that you don't really have your spokes too tight unless they're pretzelling your rims (slight exaggeration, maybe), but I am wondering whether you tune spokes on small wheels to the same pitch as you would a 700c or 27" wheel.
I have a bike with 20" wheels (four of them) and most of the spokes go "thud" rather than "ping". Should I give them a few more turns with the spoke key?