Lock Tangents

Track View > Curve Editor > Select keys on curves. > Curves: Track View Toolbar > Lock Tangents

Lock Tangents lets you manipulate handles of multiple vertices simultaneously. When Lock Tangents is active, dragging a tangent handle affects the handles of all highlighted keys. When Lock Tangents is inactive, dragging a tangent handle affects only that handle's key.

Procedure

To drag discontinuous tangent handles:

Highlight one or more keys in the Curve Editor. Hold down the Ctrl key to add to the selection set.
Click Lock Tangents to set one of the following modes:
- Off: Dragging a tangent handle affects only the single key displaying the handle.
- On: Dragging a tangent handle affects both handles of all selected keys.