Composing and arranging
What the domain tests
Composing and arranging tests the ability to make a coherent piece from limited material and to write it idiomatically for voices or instruments. Examiners look for phrase structure, harmonic grammar, rhythmic drive, texture, contrast and correct notation. An arrangement must preserve the identity of the original while suiting the new medium.
Core rules
- Build phrases in 2-, 4- or 8-bar units and mark cadences.
- Develop motifs by sequence, inversion, retrograde, augmentation, diminution, rhythmic displacement and reharmonisation.
- Plan harmonic rhythm; change chords at structural points, not every beat.
- Keep within ranges and transpositions; write idiomatic figuration.
- Score layout: systems, brackets, clefs, key and time signatures, dynamics.
Worked example
Given the motif G–A–B–A (two quavers then two crotchets) over G major. Reasoning: treat it as an anacrusis-like cell. Bars 1–2 state it with I–V. Bars 3–4 sequence it up a step with ii–V, creating a half cadence. Bars 5–6 use rhythmic augmentation (G–A–B–A in minims) over IV–I for contrast. Bars 7–8 return to the original rhythm and close V–I. Add imitation in an inner part at bar 5 but keep the bass simple.
Traps
Motif never returns; too many ideas; cadences on weak beats; parallel fifths or octaves in chorale texture; unplayable ranges; missing accidentals after modulation; a piano part that doubles the melody throughout.