The sky was overcast and bleak today, but the heat and humidity were still oppressive. Dad brought home the metronome he ordered for me online this morning. None of us knew how to use it. It has a left slider, a right winding key, and a center hand that sways like an inverse pendulum. It resembles a tumbler (?) in a way. We were stumped until we noticed a second slider on the hand itself, moving vertically to adjust the speed. The scale behind it is called the Tempo Scale – units I don't understand yet. I'll probably need my teacher to explain it; Dad couldn't help.