You can use your PC's keyboard to record melody/solo with in midi format. The recorded notes will play according to the chord-per-bar. You can then edit, if you want to, from the piano roll the notes, note length, velocity etc.

My keyboard uses the bottom 2 rows of letters A - / for recording with. You can get a feel of which notes/letters to use for your recorded solo. It is easy to make them with this technique.

Trax