there are many ways to do this, another suggestion:

copy the style to the composer, edit the ending to mute tracks leaving just drums, bass or nothing (a blank ending) and play your right hand melodies over it or instead of it.

for single songs, you save the song singly on page 3 of the save, and then load it singly on page 3 of the load to whatever position you choose. do this on floppy, then save the 10 songs on hx6.