FractMus is a freeware algorithmic-music generator, that is, it creates melodies using mathematical formulas.

Screenshot of the program

Screenshot of the program.

Since the times of Ancient Greece, people have realized that music and mathematics had a very close relationship, maybe because music is the most abstract form of art. Using mathematics explicitly to create music is nevertheless something of our time. Without the help of the modern computer it would be a daunting task (if not an impossible one) to do all the necessary calculations by hand.

via Overview | Gustavo Díaz-Jerez.