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Mus 1301 Theory I Fri., Jan. 23, 2015

Turn in Workbook p. 7-8

TODAYS TOPIC: Intervals Method #3

Interval Methods Review

Method #1: Major Scale From Do up to each scale degree forms only MAJOR & PERFECT intervals.

Method #2: Half Steps Memorize the number of half steps in interval sizes m2 (1) through P8 (12).

Intervals Method #3: Basic Intervals

A basic interval is the distance between two pitches without any accidentals.

There are seven basic intervals for each interval size, one for each letter of the musical alphabet, A-G.

Adding the same accidental to both notes of a basic interval does not change its quality.

Intervals Method #3: Basic Intervals

Using this method, you will memorize the quality of basic intervals (intervals with no accidentals).

Then, when analyzing an interval with accidentals, 1st analyze the basic version and then consider what affect the accidentals have on the intervals quality.

Method #3: Basic Intervals OCTAVES

All basic octaves are PERFECT.

If either note has an accidental on it, the octave is

NOT PERFECT.

If the accidental causes the interval to be smaller, it is DIMINISHED.

If the accidental causes the interval to be larger, it is AUGMENTED.

Method #3: Basic Intervals UNISONS

All basic unisons are PERFECT.

If one of the notes has an accidental on it, the

interval is larger than a perfect unison, thus it is AUGMENTED.

There is no such thing as a DIMINISHED unison.

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Method #3: Basic Intervals FIFTHS

All basic fifths are PERFECT, except for one, B-F, which is DIMINISHED.

With the exception of the B-F fifth, fifths are PERFECT if both notes have the same accidental on them. If both notes are natural, or sharped or flatted, the interval is PERFECT.

Method #3: Basic Intervals FOURTHS

All basic fourths are PERFECT, except for one, F-B, which is AUGMENTED.

Knowing this enables you to easily spell, write and identify fourths.

With the exception of the F-B fourth, fourths are PERFECT if both notes have the same accidental on them. If both notes are natural, or sharped or flatted, the interval is PERFECT.

Method #3: Basic Intervals SECONDS

All basic seconds are MAJOR except for two

E-F and B-Cwhich are MINOR.

Remember, adding the same accidental to both notes of a basic interval does not change its quality.

If the two notes have differing accidentals, compare the interval to its basic version and adjust the quality.

Method #3: Basic Intervals THIRDS

All basic thirds are MINOR except for three

C-E, F-A and G-Bwhich are MAJOR.

When analyzing a 3rd with one or more accidental, first analyze the quality of its basic version, then adjust its quality by adding back the accidental(s).

Memorize the BASIC 3rds

Thirds built on C, F & G are basically MAJOR.

Thirds built on D, E, A & B are basically MINOR.

INVERSION

Inversion (of an interval) = flipping it so that the bottom note becomes the top and vice versa.

The numerical size of an interval plus its inversion equals 9. (2 + 7, 3 + 6, 4 + 5)

The quality of an interval changes under inversion as follows: M becomes m; m becomes M A becomes d; d becomes A P intervals remain P. Thats why theyre PERFECT!

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INVERSION

Thus when inverted,

M6 becomes ____

m2 becomes ____

A4 becomes ____

d8 becomes ____

P5 becomes ____

INVERSION

Thus when inverted,

M6 becomes m3

m2 becomes M7

A4 becomes d5

d8 becomes A1

P5 becomes P4

Using Inversions to Solve Large Interval Questions

When asked to write or analyze a large interval (a 6th or 7th), you may find it easier to write or analyze its inversion first.

For ex., need a M7 down? Find the pitch a m2 up and write it below the given pitch.

CONSONANCE & DISSONANCE

Harmonic intervals are classified as:

Consonant = pleasing, agreeable 1, 3, 5, 6, 8

Dissonant = strident, discordant 2, 7, & 4 (over the bass note)

See p. 22 E for practice problems.

PRACTICE PROBLEMS

See Self-Test 1-6 pp. 21-23. Part A focuses on diminished and augmented intervals.

Part C offers the challenge of writing intervals downwards for which Methods #2 & #3 can help!

Part D asks you to label melodic intervals. Watch out for accidentals still in effect from earlier in the measure!

Homework due Monday

Key Signatures memorize Majors & minors! Practice intervals as needed with S-T 1-6 Do WB (workbook) pp. 9-10; on Part C, do odd-

numbered problems only. NEVER ALTER THE GIVEN PITCH!