This fun and playful melody has a very Gypsy feel. Notice all the chromatic notes in the melody and the dramatic 7th chords in the backing track. Gypsy music can go from sorrowful to happy and exciting, in this case getting a lot more upbeat and playful.
Each phrase is played over each chord so that we're actually playing through changes and not playing in one key throughout the entire piece. Improvisations are a lot of fun over this progression, using D natural minor works great when soloing but be sure to play to the changes!