Just for the experts: The natural D-minor scale looks like in the picture on the left, whereas the harmonic D-minor scale has a raised seventh as shown in the picture on the right. But that is not relevant for the five-string kantele, as it only has only the notes D-E-F-G-A anyway.
Exercise 1: Look up the chords for Dm, Gm and F in the chord chart for D-minor at the end of this book. Then try to play and sing "When Israel was in Egypt's Land":