Pitch, scales, intervals and chords: HSC Music core

What this dot point is asking

Pitch carries the heaviest technical theory in HSC Music. You are expected to know how scales are built, how to identify intervals, how triads and seventh chords are formed, and how chords combine into progressions. Music 1 students mostly need this for aural identification and to support composition and performance. Music 2 students must also read and write this material in notation and apply it in score analysis. This dot point asks you to handle pitch with precision rather than vague description.

The answer

Scales

A scale is an ordered set of pitches. The major scale follows the tone pattern T T S T T T S (for example C major: C D E F G A B C). The natural minor uses T S T T S T T (A minor: A B C D E F G A). The harmonic minor raises the seventh, giving a distinctive augmented-second gap (A B C D E F G-sharp A), and the melodic minor raises the sixth and seventh ascending but reverts descending.

Modes are scales built on different degrees of the major scale. Dorian (D to D on the white notes) sounds minor with a raised sixth; Mixolydian (G to G) sounds major with a flattened seventh and is common in folk and rock; Aeolian is the natural minor. The pentatonic scale uses five notes (major pentatonic: C D E G A) and appears across folk, pop and many world musics. The blues scale adds the flattened "blue" notes (C E-flat F F-sharp G B-flat C) and underpins blues, jazz and much popular music.

Intervals

An interval is the distance between two pitches. Name it by number (count the letter names inclusively) and quality (major, minor, perfect, augmented, diminished). The perfect intervals are the unison, fourth, fifth and octave. Seconds, thirds, sixths and sevenths come as major or minor. Useful reference points for ear training: a perfect fifth is the opening of "Twinkle Twinkle"; a major third is the first two notes of "When the Saints"; an octave is the leap in "Somewhere Over the Rainbow". You should identify common intervals by ear in aural tasks.

Triads

A triad is a three-note chord built in thirds: root, third and fifth. The four triad qualities are major (major third plus minor third, for example C E G), minor (minor third plus major third, C E-flat G), diminished (two minor thirds, C E-flat G-flat) and augmented (two major thirds, C E G-sharp). In a major key the triads on each degree are: I major, ii minor, iii minor, IV major, V major, vi minor, vii diminished. Knowing this lets you predict which chords belong to a key.

Seventh chords

Adding a fourth note a third above the fifth gives a seventh chord. The dominant seventh (V7, for example G B D F in C major) is the engine of tonal harmony because it pulls strongly back to the tonic. The major seventh (C E G B) sounds lush and is common in jazz and ballads; the minor seventh (C E-flat G B-flat) is common in funk, soul and jazz.

Progressions and cadences

Chords move in patterns. The most important progressions to recognise are I to IV to V to I (the foundation of much tonal and popular music), the I to vi to IV to V "fifties" progression, the twelve-bar blues (I I I I, IV IV I I, V IV I V), and the ii to V to I jazz cadence. Cadences are the punctuation: a perfect cadence (V to I) closes firmly, a plagal cadence (IV to I) is the "amen" close, an imperfect cadence ends on V leaving the phrase open, and an interrupted cadence (V to vi) surprises the listener.

Hearing and notating pitch

In aural tasks, work from the bass up: find the tonic, decide major or minor, then track the harmonic rhythm and listen for the cadence points. In Music 2 score analysis, label chords with Roman numerals or chord symbols, identify the key and any modulation, and connect harmonic choices to the style. Tying a progression to its genre (twelve-bar blues to rock and roll, ii-V-I to jazz) shows musicological understanding, not just labelling.