Track curves
The same range on three tracks — 20 Hz to 20 kHz. The marks sit at 100 Hz, 1 kHz and 10 kHz, so you can see where each track puts them without touching anything. Drag one and the other two follow to the same value.
FormData
Events
Try: tab to a slider and use the arrow keys, Page↑/Page↓,
Home/End. On the dual slider, hold Shift to move the lower
handle.
input fires while dragging, change on release.