CH 5- Triads and Figured bass

Chords and Triads

  • “Chord” is often used with a prefix designating specific number of component pitches

    • Hexachord= Six notes

    • Pentachord= Five notes

    • Tetrachord= Four notes

    • Trichord= Three notes

    • Dyad= Interval (two notes)

  • Chords of three notes form the basis of tonal music

    • A trichord can refer to any collection of three pitches

    • A trichord is different from a triad because triads are symmetrical and stacked in thirds

  • A triad is named for its root

Qualities of Triads

  • Triads can be major, minor, augmented, or diminished

    • If given name of “Major”, it has a relationship to the major scale

  • Middle and top notes of a triad are referred as “chordal third” or “chordal fifth”

    • Distinguishes them from third and fifth notes of a scale and from intervals of the same size

  • A minor triad is based on first, third, and fifth scale degrees of a minor scale

  • The middle note of a major triad can be lowered to make a minor triad

    • Rules:

      • If third is natural → make flat

      • If third is sharp → Make natural

      • If third is flat → Make double flat

  • To make a diminished triad from a major triad, you lower both the third and the fifth

    • For a minor triad- only lower the 5th

  • Raising the root of a major triad will create a diminished traid

    • Helpful when the name of the diminished triad is a half step higher than a major triad

    • you CANNOT change the letter name of the root

  • To create a augmented triad from a major triad, raise the 5th SD of Major triad

  • Augmented and diminished traids are primarily categorized by outside intervals rather than relation to a scale

    • Ex. Diminished triad is Diminished 5th from root to fifth; same as augmented

  • Augmented and Diminished triads are NEVER used in construction of triads

Triad Qualities

Quality

Major Triad

Minor Triad

Dim. Triad

Aug. Triad

Upper Third

m3

M3

m3

M3

Lower Third

M3

m3

m3

M3

Outer Interval

P5

P5

Dim. 5th

Aug. 5th

Identifying Triad Qualities

  • Compare triad to a triad you already know when asked triad quality

  • Different spacing of notes of a triad does not alter the quality

Inversion of Triads

  • Root position triad has the root as the lowest note

  • First inversion has the third as the lowest note

  • Second Inversion has fifth as the lowest note

  • Changing the inversion of a chord does not alter pitch content, name, or quality

  • When inverted, a triad will always contain the interval of a fourth

  • To find root of inverted triad, find the top note of the interval of the fourth; always the root

Figured Bass

  • Code/ unique combination of intervals that stand for particular triad in specific inversion

    • Describe intervals that occur above the bass note

  • Abbreviated versions of the number are used to represent the inversions

    • When there is no number below the chord, it is in root position

Root

1st Inv.

2nd Inv.

Complete

5

3

6

3

6

4

Abbreviation

6

6

4

  • Numbers with a slash indicate means the note corresponding to the interval should be raised a half step from the key signature

    • Flat sign is used to lower the note

  • Accidentals by itself represent the third up from the bass note

  • Root position triads don’t require figured bass symbols

  • “6” indicates that the triad is inverted

  • Figures written under the bass line are performed by a low pitched instrument

  • Keyboard player reads bass line and improvises accompaniment based on figures

    • Texture is created by keyboard player is a keyboard realization

    • Instruments whos job it is to “realize” the figured bass were commonly called the Basso

Finding Root and Building Triad

  • Determine chord inversion

  • Six in figured bass in an interval above bass

    • Bass note is chordal third

  • Go down a third from given bass note