Chapter 5

Minor Keys and the Diatonic Modes

Parallel Keys: Shared Tonic

• Compare the two examples below and their pentachords (first five notes of the scale).

• The two passages are written in parallel keys - E major and e minor.

• Parallel keys share the same tonic.

• Parallel keys often appear within a single piece or movement to reflect a change of mood.

Relative Minor: Shared Key Signatures

• Compare the two excerpts below.

• These excerpts are in relative keys: they share a key signature but have different tonics.

• Many pieces in major keys include passages in either parallel or relative minor, and pieces in minor keys likewise often include passages in the relative or parallel major. The motion between keys creates musical interest by varying the color and mood.

• Relative keys have different tonics, but they share the same key signature and diatonic collection.

Finding the Relative Minor Key

• To find the relative minor of any major key, identify scale degree 6 of the major scale: that pitch is the tonic of the relative minor.

• Alternatively, the tonic of the relative minor scale is a minor third (three half steps) lower than the tonic of the relative major.

Finding the Relative Major Key

• To find the relative major of any minor key, identify scale degree 3 of the minor scale: that pitch is the tonic of the relative major.

• Alternatively, the tonic of the relative major is a minor third (three half steps) up from the tonic of the minor key.

Identifying the Key of a Musical Passage

• Look at the key signature, and think of both the major and minor key associated with that signature.

• Look at the beginning of the melody and bass line for motion to and from either the major-key or minor-key tonic.

• Check the end of the melody and bass line for motion to the tonic.

• Note any accidental (typically written to create a leading tone in minor).

• Key signatures for parallel keys differ by three accidentals.

• To find the key signature of for the a parallel minor of a major key, you can move three steps counterclockwise around the circle of fifths.

Summary

• Parallel keys share the same tonic and have key signatures that differ by three accidentals.

• Relative keys share the same key signatures and diatonic collection. Their tonics differ by a minor third (three half steps).

Variability in the Minor Scale

• The bracketed scales in measures 41 and 45 share the same minor pentachord (first five notes of the scale), but their upper tetrachords differ.

• Measure 41is an example of an ascending melodic minor scale (raised scale degrees 6 and 7).

• Measure 45 illustrates a natural minor scale.

• By raising and lowering scale degrees 6 and 7, the minor scale can demonstrate a lot of flexibility.

The Forms of Minor

• Natural Minor: accidentals exactly match the key signature of the relative major. A distinctive aural quality of this scale is that it lacks a leading tone.

• Harmonic Minor: raises scale degree seven by a half step to create a leading tone. The unique quality of this scale is the Augmented second between scale degrees six and seven. This scale follows the same form both ascending and descending.

• Melodic Minor: In it's ascending form, scale degrees six and seven are raised by a half step. It's descending form is identical to natural minor. The ascending form sounds like a major scale with a lowered scale degree 3.

• To change a natural minor scale to harmonic minor, raise scale degree 7 by a half step.

• In harmonic minor, accidentals may be mixed and double sharps may be necessary.

Hearing Minor Scale Types

• First listen for the b3 to establish if the scale is minor or major.

• Then listen for the leading tone: natural minor has no leading tone.

• Harmonic minor will feature an Augmented Second (A2) between the submediant ad the leading tone.

• An ascending melodic minor scale will sound the same as major with the exception of the b3.

Writing Minor Scales

• Write the pitches on the staff from tonic to tonic.

• Create a natural minor scale by using either your knowledge of key signatures or by following the intervallic structure of W-H-W-W-H-W-W.

• Raise scale degrees 6 and 7 as necessary. How you follow this step is contingent of the type of question being asked.

Scale Degrees in Minor

• Scale-degree names in minor are identical to those in major with two exceptions.

• When scale degree 7 is a whole step away from tonic (as it is in natural minor), it is referred to as a subtonic - not a leading tone.

• When scale degree 6 is raised (as it is in melodic minor), it is referred to as the raised submediant.

Minor Pentatonic Scale

• The minor pentatonic scale includes scale degrees 1, 3, 4, 5, and 7. (Sometimes written as 1,b3, 4, 5, and b7).

Modes of the Diatonic Collection

• After hearing this melodies, sing tonic.

The Relative Identification of Modes

• There are six traditional diatonic modes, sometimes referred to as the church modes.

• These modes share the same diatonic collection as a major scale, but each mode begins with a different starting pitch.

• The diatonic collection of pitches from C to C (with no sharps or flats) may be rotated to begin with any pitch. Each rotation forms a diatonic mode. These are, in order from C: Ionian, Dorian, Phrygian, Lydian, Mixolydian, and Aeolian.

• To identify a mode with the relative method, think of the major key associated with the work's signature. If the melody rests of scale degree 1 as its most stable pitch, it must be major (Ionian). If it rests on scale degree 6, it must be minor (Aeolian). But, if it rests on scale degree 2 and scale degree 2 seems to function as the most stable pitch, then the melody is in Dorian mode. (Phrygian - scale degree 3, Lydian - scale degree 4, Mixolydian - scale degree 5)

The Parallel Identification of Modes

• We are used to listening to the major and minor scales, we sometimes hear modes as alterations of these more familiar scales.

• Modes that are based on a major pentachord: Ionian, Mixolydian (b7), Lydian (#4)

• Modes that are based on a minor pentachord: Aeolian, Dorian (#6), Phrygian (b2).

Review - Write a Dorian Scale beginning on G:

• Relative method:

• Write note heads on the staff from G to G

• Remember that Dorian begins on scale degree 2 of a major scale. G is scale degree 2 of F major.

• Since the key signature of F major has one flat, add a flat to B.

• Parallel Method

• Remember that Dorian sounds like natural minor with a raised sixth scale degree.

• Write a G natural minor scale (Bb and Eb).

• Raise scale degree 6 by changing Eb to E natural

Twentieth-Century and Contemporary Modal Practice

• The diatonic modes were not used much in the 18th and 19th centuries.

• There has been a renewed interest in modal music - mainly in jazz and popular music.

• The locrian mode was used more frequently - making it a seventh diatonic mode.

• Music can shift modes just like it can shift from major to minor.

Questions for Review

• What similarities do relative and parallel minor share with major? How do they differ from each other?

• What are the differences between the three minor scale types? How are these differences reflected in the scale-degree names?

• Given a key signature, how do you know which minor key it represents?

• Given a minor key, how do you find the relative major?

• How do the diatonic modes differ from major and minor scales? Describe the relative and parallel methods for identifying and spelling modes.

• Given a pitch and a mode to build on it, what steps should you follow?

• http://www.musictheory.net/exercises/keysig

• http://www.musictheory.net/exercises/ear-scale

• http://gmajormusictheory.org/Listening/scales/scales.html

Websites for Practice

Terms You Should Know

• Diatonic Modes: Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian, Locrian

• Major and minor pentachords

• minor scales: harmonic, melodic, natural

• mode

• parallel major and parallel minor

• pentatonic scales

• relative major and relative minor

• subtonic