Not sure exactly what you are trying to do here (other than confuse me on the last day of '23 ... which you succeeded at!), but the mistake is in how you have defined the Melody strings. The syntax for the notes in a Solo or Melody are NOT the same as that for a "regular" sequence
So, in your definition of MO
Melody Define M0 \
4 c- 80; \
4 d- 80; \
4 e- 80; \
4 f- 80;
you have actually created the notes C- and G# (note 80). So, you are getting some very interesting harmonies
If you want to micromanage note volumes (actually they are velocities, but that is a different discussion) you have to do it like this:
Melody Define M0 \
4 c-/80; \
4 d-/80; \
4 e-/80; \
4 f-/80;
BTW, I think the notation above is slightly deceiving since it implies a 4 bar sequence. Better would be:
Melody Define M0 4 c-/80; 4 d-/80; 4 e-/80; 4 f-/80;
And, since the duration is being repeated:
Melody Define M0 4 c-/80; d-/80; e-/80; f-/80;
Since you are dropping all the notes by a single octave, try using the OCTAVE option when you create the melody (Octave 3 or Octave 4) leave out the "-"s.
And, finally, since the velocity is just using the default:
Melody Define M0 4 c; d; e; f;
Hope this helps.