The Orchestration Challenge 4 Melody and Midi file are posted at the links below.
The melody is very simple and predictable harmonically, but I think it should have many reharmonization possibilities, and plenty of room for thematic development.
The 'B's in measure 4 and 5 are natural. All other 'B's are flat, including all 'B's in measure 6. You will hear it in the midi file anyway.
Have fun and let me know if you have any questions.
Thanks a lot, Linda