Percussion on the Grid

I scrambled down from the sill and trotted over to the tall speaker resting on the wooden floor! Its mesh front buzzed with a faint, rhythmic vibration. Curious, I leaned in and tapped the woven fabric with my soft boot. It made a deep, muffled thump! Right nearby lay a smooth wooden ruler and an empty ceramic mug. I picked up the ruler with both hands, swinging it lightly so the tip clicked against the glossy rim of the mug—ping! Then I stomped one foot against the speaker mesh—thud! Ping, thud, ping, thud! I bounced along to my own clattering little beat until the ruler wobbled and clattered onto the floor!