Hitting a half-full insulated klean kanteen water bottle with various objects. First short set with my fingertip, second set with the side of my varnished tin starbucks coffee mug and the third set with the side of a standard 3/8" plastic sharpie marker. According to my synth, this is extremely close to, if not spot-on with a d-natural (294 hz).
Author: Depwl