Very often a large part of composition involves expanding a very short simple idea into an entire work. A motif may be just a few notes, but careful development can make a little go a long way.
Development may be achieved by thinking about unity and variety. If the motif is repeated that is unity. If a contrasting motif follows (An answer
) that is variety. There are several stages in between if a motif is repeated but with varying degrees of changes. Using the different musical elements (e.g. melody, rhythm, harmony, timbre and dynamics) there are many possibilities of creating logical development. You can use combinations of exact or approximate repetition of different elements.
In composition (as opposed to arranging and orchestration) it makes more sense to start with just the three main elements (melody, rhythm and harmony). It is useful to combine repetition of one element with variations of one or more of another:
Repetition of: |
Variation of: |
Melody |
Rhythm and/or harmony |
Rhythm |
Melody and/or harmony |
Harmony |
Melody and/or rhythm |
In addition you can use approximate repetition, especially of melody. This is often necessary if the harmony is changing and can be done by:

In La Cucaracha
the opening motif is firstly repeated then followed by an answer (motif 2). Motif 1 then appears again slightly altered to fit the harmony (motif 1a), but the main contour of the melody is retained. This is then repeated (unity – it follows the same method as the opening statement) and is then followed by the another answer (motif 2a) which combines unity and variety. Unity is achieved by using the same rhythm as motif 2 but with different notes and intervals. There is already tension at this point due to the V7 chord. As the opening 4 bar phrase has a cadence from I to V7 on bar 4, we expect (and receive) the second 4 bar phrase to cadence at the same point. This is unity that is totally appropriate to a folk dance tune.
In Autumn Leaves the opening 4 note motif is repeated in sequence with almost exactly the same rhythm, one step lower each time. This is not an exact transposition, it is atonal transposition. The first three notes of the opening motif are the first, second and third degrees of G minor, so the third degree is minor. The first three notes of the sequenced repeat of this motif are the first, second and third degrees of F mixolydian (the scale that corresponds to F7) so the third is major.
This 8 bar A
section is repeated, so that the rhythmic repetition of the motif builds tension which is release at the first bar of the B
section

Exercise:
You will probably find that:
folkfeel, and though still valid as an art composition, remove it from the realms of commercial composition.
Exercise:
Replace the opening motif of (b) with an original motif so that the answer still makes sense.