If we label our musical materials, ideas, or sections with the letters of the alphabet we can show how musical forms are created.
Any single section of music, consisting of phrases or other musical sections, we can call A. This musical section can be repeated to create an AA form.
If we instead chose to add a new section, B, we would have the musical form AB. This would be two contrasting musical sections.
If we chose to add another A to an AB form, but this time with variation we would have the form ABA'. (The ' is used to indicate variation).
With the processes of repetition, contrast and variation there can be many musical forms.
- Strophic - AAA, etc.
- Binary - AB
- Ternary - ABA
- Rondo - ABACA, or ABACADA
- Arch - ABCBA
- Sonata Form - Exposition: (Theme Group 1 - Theme Group 2) --- Development --- Recapitulation: (Theme Group 1 - Theme Group 2)
- Sonata Rondo - ABA - C - ABA