Create accompaniment textures from a chord scheme, including block chords, broken chords, an Alberti bass, arpeggios and a melody-and-accompaniment layout, choosing a texture to suit the style

What this dot point is asking

SEAB wants you to turn a chord scheme into an effective accompaniment, using textures such as block chords, broken chords, an Alberti bass and arpeggios, in a melody-and-accompaniment layout, and to choose a texture that suits the style. The central insight is that the same chords can be presented in many textures: harmonisation decides the chords, but accompaniment decides how those chords are spread out in time and register to support the melody.

The answer

From chords to accompaniment

Once you have a chord scheme (say I, IV, V, I), you must decide how to play those chords. The notes of a chord can be sounded together or one at a time, low or high, sustained or repeated, and each choice gives a different texture and mood. This is the art of accompaniment.

The main accompaniment textures

• Block chords: all the notes of each chord played together (sustained or repeated). Simple and strong, suited to hymns, chorales and bold or stately music.
• Broken chords: the notes of each chord played one after another rather than together, giving a gentler, flowing feel suited to ballads and lyrical pieces.
• Alberti bass: a specific broken-chord pattern, usually lowest, highest, middle, highest, repeated steadily; light and elegant, characteristic of the Classical style.
• Arpeggios: the chord spread across a wide range, low to high and back, giving a rich, sweeping, harp-like texture suited to Romantic or expressive music.

Melody-and-accompaniment texture

The most common layout is melody-and-accompaniment (a homophonic texture): the main tune in one part (often the top) with the other parts providing chordal support underneath. The melody is the focus; the accompaniment supplies the harmony and rhythm around it.

Keeping balance

The accompaniment must support, not overpower, the melody. Keep it softer than the tune, in a lower or less prominent register, and avoid busy or high figures that compete with the melody. Good balance lets the melody sing while the accompaniment fills in the harmony.

Choosing a texture for the style

Match the texture to the music: block chords for a hymn or anthem, broken chords or an Alberti bass for a Classical or gentle piece, sweeping arpeggios for a Romantic or dramatic mood, and a steady repeated pattern for a pop or dance feel.

Examples in context

Example 1. A Classical sonatina with an Alberti bass. A Classical keyboard sonatina typically sets a clear melody in the right hand over a steady Alberti bass in the left, the broken-chord pattern keeping the harmony present and the texture light. It is the standard example of the Alberti bass in a melody-and-accompaniment texture.

Example 2. A Romantic nocturne with spread arpeggios. A Romantic nocturne often floats a singing melody over wide, pedalled arpeggios that spread each chord richly across the keyboard. It shows how an arpeggiated accompaniment creates a warm, expressive backdrop very different from plain block chords.

Try this

Q1. Explain the difference between block chords and broken chords. [2 marks]

• Cue. Block chords sound all the notes of a chord together; broken chords sound the notes one after another, giving a more flowing texture.

Q2. Describe an Alberti bass. [2 marks]

• Cue. An Alberti bass is a broken-chord pattern playing the chord notes in a repeating order (typically lowest, highest, middle, highest), light and characteristic of the Classical style.

Q3. Describe two ways to stop an accompaniment from overpowering the melody. [2 marks]

• Cue. Play it softer than the melody and keep it in a lower or less prominent register, avoiding busy or high figures that compete with the tune (any two).