Longer, heavier gauge piano strings need larger, heavier hammers to sound good and have sufficient power. Shorter, lighter gauge strings need smaller, lighter hammers. To make the full range player-friendly, the mechanics can be designed to work well without compensation at the light end and with key balancing weights added elsewhere as needed.

Music History quiz: What is the single most notable feature in a modern grand action? If we answer “double escapement”, then as piano historians we can high five. But as piano technicians we may be quietly confused. In our training, did we learn how to analyze, trouble-shoot, or regulate double escapement? Well we did, if by double escapement we...