[Listening extract audio not available in printed QP] A composer writes four piano pieces, each based on a different type of scale. (a) Describe the differe...

(a) Diatonic vs. chromatic scales [2]

A diatonic scale consists of seven notes arranged in a specific pattern of tones (whole steps) and semitones (half steps) within an octave. [1] The two most common types are the major scale (tone-tone-semitone-tone-tone-tone-semitone) and the natural minor scale (tone-semitone-tone-tone-semitone-tone-tone). Each diatonic scale uses only the notes belonging to its key signature, with no additional sharps or flats.

A chromatic scale, by contrast, uses all twelve semitones within an octave. [1] Every step is a semitone, so the scale includes every possible note (all the white and black keys on a piano within one octave). While a diatonic scale is selective - choosing seven specific pitches to create a particular tonal character - the chromatic scale is all-inclusive, moving through every available pitch equally.

(b) Whole-tone scale [1]

The distinctive feature of a whole-tone scale is that all intervals between adjacent notes are the same size - every step is a whole tone (two semitones). This produces a scale of six notes per octave (e.g., C-D-E-F sharp-G sharp-A sharp). Because there are no semitones, the scale has no leading note pulling toward a tonic, which gives it an ambiguous, floating, dreamlike quality with no strong sense of key or resolution. There are only two possible whole-tone scales (starting on C or C sharp; all other starting notes produce one of these same two sets of pitches). The whole-tone scale was famously used by Claude Debussy and other Impressionist composers.

(c) Period or tradition using modal scales [1]

Acceptable answers include any one of the following:

• Medieval period: modal scales (Dorian, Phrygian, Lydian, Mixolydian, Aeolian, Ionian, Locrian) were the basis of Western music before the major-minor tonal system was established
• Renaissance period: polyphonic vocal music (e.g., by Palestrina, Josquin) was composed using modes
• Plainchant / Gregorian chant: the earliest notated Western music, sung in churches, used the church modes
• Folk music: many folk traditions around the world use modal scales rather than major/minor keys
• Jazz: modal jazz (e.g., Miles Davis's Kind of Blue) uses modes as the basis for improvisation rather than chord changes
• Impressionist music: composers like Debussy drew on modes for their distinctive harmonic colours