While working on my third animation in Blender (a couple of fighter craft taking off from the launch platform), I wanted to smooth out the transition from VTOL to horizontal flight by slightly shifting the timing of a keyframe. I opened the dope sheet, thinking it would be an easy fix, but I found that the key frame markers are all gone, despite the keyframes still being there (see the timeline for proof of that). All I can see is a few bar graphs. Is there some weird setting I've accidentally enabled? Can I switch back to the normal visualization of keyframes that is easy to work with?