To view keys in the timeline, select an object with keyframes set on any of its parameters.
The keys appear as red lines in the timeline, with keyframes being drawn at their exact position in time.
The thickness of the lines depends on the length of the time range or how much you're zoomed in to the timeline: the smaller the time ranged displayed, the thicker the lines appear.
When you set keys in an animation layer, the keys appear as blue bars in the timeline. The keys are blue to remind you that you're animating in a layer, and not the base layer where the keys are red. You can, however, edit the layer keys in the timeline in the same way as you can for the base layer.
For more information, see Animation Layers.
Choosing the Type of Keys to View in the Timeline
To choose which type of keys are displayed in the timeline:
Right-click in the timeline and choose an option from the Show Keys menu.
For a description of each option, see Timeline Dopesheet Preferences. You can also set the default type of keys that are displayed by setting it in the preferences.
If the type of parameters for which you want to display keys are not in this menu (such as for shapes or constraints), you can make them keyable or put them in a character key set, then select the Keyable Parameters or Current Character Key Set option in the Show Keys menu.
Viewing Audio Waveforms in the Timeline
If the selected object has one or more audio clips loaded in its animation mixer (see Audio and Animation), you can display waveforms for them in the timeline. This helps you synchronize the animation with the sound because you can easily see where each audio clip occurs in time.
