Complete all editing and Save Project File AS, giving it a unique # or name, so as not to overwrite prior saves. Using Save Project Files (no AS) will overwrite. Then you can restore a project to the state it was in when saved. Just double-click the VPJ file (which isn't playable).
1. Place a split at the start and end of a song
2. Right-click within the split-out area and COPY
3. Click the + sign on the Sequence 1 tab above the timeline to open a new, blank sequence 2
4. Position the scrubber (red line) at the head of the track
5 Right-click in its Video Track 1 area and PASTE (insert)
Export Sequence 2, giving it a name
Delete Sequence 2 and follow the same steps for each tune