1. Melody: 72 modes with 7 notes out of 12 tetrachords (more if we count special modes with 5, 6, 8, 9 or 10 notes).
2. Meter: 15 most common meters.
3. Rhythm: at least 20 different rhythm combinations in each of the meter.
4. Harmony: three-note chords (4 versions and their inversions), four-note chords (7 versions and their inversions), five-note chords (11 versions and their inversions).
5. Registration: 4 stop families and their combinations.
6. Texture: 1 layer (5 choices - solo voice, intervals, three-note chords, four-note chords, and five-note chords), 2 layers (20 choices), 3 layers (16 choices).
7. Form: Period, Simple Binary, Simple Ternary, Compound Binary, Compound Ternary, Variations, Rondo, Sonata, Rondo-Sonata etc.
If we multiply the numbers in each of the category with the number of versions in them, we get over 3 billion (with a B!) choices to make (and I most certainly missed some of the other things, such as octave range or variety of stops in pitch level).
With such a huge variety of choices, a lot of people feel rather lost. What can you do then?
Don't worry about these infinite possibilities. Just pick one element from each of these categories that you are familiar with and create something today.
1. Melody: natural major scale from C.
2. Meter: 2/4.
3. Rhythm: one quarter-note and two eighth-notes.
4. Harmony: three-note 1st inversion major chords.
5. Registration: Principal 8'.
6. Texture: 1 layer - three-note chords (in the treble octave played by the right hand).
7. Form: Period - 8 measures total (2 sentences of 4 measures each - question/answer style - start and end on the C note).
When completed, this exercise might look something like this: