After some more testing … and subsequent bug fixing … here are proto-melodies 2 and 3 …
Firstly a four bar melody in C major over one octave in 4/4 time:
Magical Muzak Maker - Proto-melody 2
Secondly, another four bar melody in C major and 4/4 time, this time using a range of 3 octaves:

Magical Muzak Maker Version - Proto-melody 3
One thing I’ve noticed from these melodies (and many of the others generated while bug fixing) is the apparently too common insertion of very long notes. Cosmetically these could be improved in the score by using dotted notes in the ties, which should be fairly easy to implement, but I’m not too worried about that aspect. What I am slightly concerned about is that, although I don’t think the long notes are chosen any more frequently than any of the other note lengths, when one or two long notes are chosen they tend to dominate the resulting melody too much. For the next version I will add an option to weight the note selection towards the shorter notes.
For information, the current version of the Magical Muzak Maker (Alpha 1) can select notes and rests of the following lengths:
Whole – Semibreve
Half – Minim
Quarter – Crotchet
Eigth – Quaver
Sixteenth – Semiquaver
The plan is future versions will add further shorter lengths and “in-between” lengths such as dotted notes, triplets and so on.
If on the very rare chance either of these melody is not original I would be interested to find out. If either of these melody plagiarises your own music then apologies … but well, in that case your music could have been written by a very simple pseudo-random alogrithm.