Green lines are anchors: "this MIDI moment = this recording moment". Between two anchors the MIDI's tempo is scaled so it fits; the label under the lanes shows MIDI bpm → resulting bpm. ⚠ = a stretch changed by more than 5%; that usually means an anchor sits on the wrong bar. Thick lines are your (manual) anchors, thin ones were placed automatically. Red-shaded 30 s windows fit poorly.
0:23.2 or 23.2), or pressing R / M to drop a mark at the playhead while listening.
The ▶ next to each mark plays just that track from the mark. Link (Enter) makes them one anchor: that MIDI moment now plays at the recording mark. Esc clears the marks.