# Music Theory for Melodies from 10,000 feet
If you want a diatonic melody (one based around major/minor scale), you'll have a bunch of chords in that key. If your key is C major, so your notes in your scale are C D E F G A B, these are called the scale degrees, root, second, third, fourth, fifth, sixth, seventh respectively. To form a C code, we take the root, third, and fifth. If we did this in the C minor scale (C D Eb F G Ab Bb), we would get C minor. Similarly to make any triad, we start with one note, e.g. D, then add the note two degrees up (F in the case of D minor), and four degrees up (A in the case of D minor). We can do this for each note in the scale. In the C major scale we get C Dm Em F G Am Bdim. Observe that some are major and some are minor. In C minor, we get Cm D° Eb Fm Gm Ab Bb.

Now when composing a melody, the strongest note is the root. (In C major, this is C.) Then F and G are very harmonious with C (too much for many cases). B and D are the least harmonious. E and A are in between. When on e.g. B and D, the melody will feel like it wants to move to C, or possibly to E. So in general, you want to think about where the C's will go, then where the F and G go, and then where the less stable tones go. You want to think about the harmonic rhythm: the places where the strongest notes, go. Possibly you want to reinforce the harmonic rhythm by playing chords on those notes (or perhaps playing the harmony with other parts).