[Music Theory] chapter 07: triads

what are the three methods you can use to spell triads?

- interval - C major method - key signature

minor triad

a triad with a minor third between the root and third, a major third between the third and fifth, and a perfect fifth between the root and the fifth. corresponds to 1, b3, and 5 of a minor scale.

augmented triad

a triad with major thirds between the root and thirds and between the third and fifth, and an augmented fifth between the root and fifth.

diminished triad

a triad with minor thirds between the root and third and between the third and fifth, and a diminished fifth between the root and the fifth.

inversion (chordal)

a voicing in which a chord member other than the root is the lowest-sounding pitch.

key concept by itself, an accidental in figured bass always affects __________.

by itself, an accidental in figured bass always affects the note a third above the bass (not necessarily the third of the chord). figure 7.14

true or false when the triad is not arranged in thirds, we do not use the names "root," "third," and "fifth" like we do in root position.

false we speak of the root, third, and fifth of a triad, even when the triad is not arranged in thirds.

basso continuo

figure 7.12

key concept what do the numbers of figured bass represent?

figured bass consists of a bass line with numbers written under it or over it; the numbers represent the intervals to be played above the bass to make the chords. figure 7.13

what do major and minor triads have in common?

in both major and minor triads, there is a P5 between the root and the fifth.

summary in major keys, - triads on scale degrees 1, 4, and 5 are __________. - triads on 2, 3, and 6 are __________. - the triad on 7 is __________.

in major keys, - triads on scale degrees 1, 4, and 5 are major. - triads on 2, 3, and 6 are minor. - the triad on 7 is diminished.

summary in minor keys (harmonic minor), - triads on 1 and 4 are __________. - triads on 5 and b6 are __________. - triads on 2 and 7 are __________. - the triad on b3 is usually __________, featuring the diatonic b7 rather than the leading tone (7)

in minor keys (harmonic minor), - triads on 1 and 4 are minor. - triads on 5 and b6 are major. - triads on 2 and 7 are diminished. - the triad on b3 is usually major, featuring the diatonic b7 rather than the leading tone (7)

key concept when playing or writing music from figured bass, what chord tones should you use?

when playing or writing music from figured bass, use chord tones that are diatonic in the key (that fall within the relevant scale), unless an accidental appears in the figure.

key concept when triads are spelled in thirds, what are the intervals in the triad?

when triads are spelled in thirds, the interval between the lowest pitch and the highest is a fifth. the middle pitch lies a third above the root.

key concept how can you place Roman numerals in context?

when using Roman numerals, always indicate the key to the left (as in example 7.4) to place the numerals in context. write an uppercase letter for major keys and a lowercase letter for minor keys.

what are three ways in which you can refer to triads?

you can refer to triads in a certain key by the scale degree on which they are built, by their scale degree name, and by Roman numerals.

key concept next to a number, an accidental tells you to __________.

next to a number, an accidental tells you to alter that note. e.g., #6 means to raise the note a sixth above the bass a chromatic half step, b3 means to lower the note a third above the bass a chromatic half step. figure 7.14

how and why is the 5-3 figured bass symbol simplified?

the 5-3 symbol is the most common, so it is often left out.

how and why is the 6-3 figured bass symbol simplified?

the 6-3 symbol is often shortened to just 6, with 3 understood to be the remaining interval.

how and why is the 6-4 figured bass symbol simplified?

the 6-4 symbol is less common, so it is not shortened, to avoid confusion with 6-3.

why are the numerals 5 and 3 used to indicate a chord in root position?

the numerals 5 and 3 are used to indicate a chord in root position because the two higher notes are a fifth and a third above the lowest note, which is, in this case, the root.

why are the numerals 6 and 3 used to indicate a chord in first inversion?

the numerals 6 and 3 are used to indicate a chord in first inversion because the two higher notes are a sixth and third above the lowest note, which is, in this case, the third.

why are the numerals 6 and 4 used to indicate a chord in second inversion?

the numerals 6 and 4 are used to indicate a chord in second inversion because the two higher notes are a sixth and fourth above the lowest note, which is, in this case, the fifth.

fifth

the pitch in a triad that is five scale steps above the root.

key concept what two ways can chords sound?

the pitches in a chord usually sound all at once, but they may also appear in succession.

which version of the triad is the most weak?

the second-inversion triad is inherently weaker than root position or first inversion, because of its dissonant harmonic fourth between the bass and an upper voice.

how do the triads built above the scale degrees of a minor scale change when you raise the seventh scale degree to create a leading tone?

the triads on 5 and 7 become major and diminished in quality, respectively (example 7.7b).

what can you do to help identify the root and Roman numeral of an inverted triad?

to help identify the root and Roman numeral of an inverted triad, think about how the pitches of the chord would be notated if they were in root position. you might write the pitch classes on a separate staff and stack them in thirds (example 7.11).

key concept what trick can you use to identify the root of an inverted chord?

to identify the root of an inverted chord, look for the interval of a fourth. the upper note of the fourth is the root.

how do you indicate an augmented triad?

triads are abbreviated with a + for augmented.

how do you indicate a diminished triad?

triads are abbreviated with a [0] for diminished.

how do you indicate a minor triad?

triads are abbreviated with a lowercase "m" for minor.

how do you indicate a major triad?

triads are abbreviated with an uppercase "M" for major.

how are triads named?

triads are named by the letter name of their root combined with their quality, or abbreviated so that the capital letter name stands for major; an added lowercase "m" stands for minor; a [0] for diminished and + for augmented.

what are the qualities of triads built above the scale degrees of a minor scale?

triads built above the scale degrees of a natural minor scale have their own set of qualities, as shown in example 7.7a. minor: 1, 4, 5 major: b3, b6, b7 diminished: 2

what are the steps you can take to spell triads by key signature?

1. imagine the root of a major or minor triad as the tonic in a key; the upper notes lie in the scale. 2. for a major triad, think of the root's major key signature and write 1, 3, and 5. 3. for a minor triad, think of the root's minor key signature and write 1, b3, and 5. 4. spell a diminished triad by lowering the fifth of a minor triad a chromatic half step. 5. spell an augmented triad by raising the fifth of a major triad a chromatic half step.

what are the steps you can take to spell triads by the C major method?

1. memorise the qualities of each triad in C major, as the piano white keys or plain note heads on the staff (example 7.9a). 2. use this information to build other triad types (parts b-d).

what are the steps you can take to spell triads by interval?

1. root. 2. P5 for major or minor triad, d5 for a diminished triad, A5 for an augmented triad. 3. M3 for a major triad, m3 for a minor triad, m3 for a diminished triad, M3 for an augmented triad. (example 7.8)

key concept what are the labelling conventions for using Roman numerals to indicate a chord's scale-degree position and quality?

Roman numerals are a handy way of labelling both a chord's scale-degree position (I to vii[0]) and its quality: a capital numeral indicated a major triad (I, IV, V), and a lowercase numeral indicates a minor triad (ii, iii, vi). for diminished triads, add a superscript circle to the lowercase numeral (vii[0]); for augmented triads, add a small + to the capital numeral (III+).

triad

a chord made from two stacked thirds.

arpeggio

a chord played one pitch at a time.

root position

a chord voiced so that the root is in the bass.

chord

a group of pitches sounded together. in common-practice harmony, chords are generally built in thirds.

major triad

a triad with a major third between the root and third, a minor third between the third and fifth, and a perfect fifth between the root and fifth. corresponds to 1, 3, and 5 of a major scale.

key concept a slash through a number means __________.

a slash through a number means to raise the note. figure 7.14

how are chords in first inversion indicated?

chords in first inversion are indicated with the numerals 6 and 3.

how are chords in root position indicated?

chords in root position are indicated with the numerals 5 and 3.

how are the chords in second inversion indicated?

chords in second inversion are indicated with the numerals 6 and 4.

key concept if the root of a triad is the bass, the triad is in __________. otherwise, the triad is in __________.

if the root of a triad is the bass, the triad is in root position. otherwise, the triad is in inversion.

key concept if the third is in the bass, the triad is in __________. if the fifth is in the bass, the triad is in __________.

if the third is in the bass, the triad is in first inversion. if the fifth is in the bass, the triad is in second inversion.