Why is ii6 always used instead of ii?

In tonal music, the use of the ii6 chord as a predominant chord is a common practice. This article explores the reasons behind its prevalence and the advantages it offers in harmonic progression. The information presented here is based on reputable sources such as Music Stack Exchange, Open Music Theory, and Wikipedia.

Harmonic Function

One of the main reasons for the preference of ii6 over ii is the harmonic function. In tonal music, predominant chords serve as a transition away from tonic function toward dominant function. The ii6 chord acts as a strong predominant chord, while the ii chord is considered a weaker predominant chord.

Bass Note

Another factor that distinguishes ii6 from ii is the inversion of the chord. The ii6 chord is in first inversion, which means that the bass note is the third of the chord. For example, in the key of C major, the ii6 chord would have an F in the bass. This inversion gives the ii6 chord a different sound compared to the root position ii chord.

Resemblance to IV

The inversion of the ii chord to ii6 creates a chord voicing that resembles the IV chord. The lowest note of the ii6 chord, F-A-D in the key of C major, shares two common tones (F and A) with the IV chord (F-A-C). This resemblance to the IV chord contributes to the tonal stability and familiarity of the progression.

Color and Resolution

Using ii6 instead of ii adds a minor color to the harmonic progression. The presence of the sixth (D in the key of C major) creates a minor flavor, contrasting with the major quality of the other chords in the progression. Additionally, the ii6 chord provides a smoother resolution to the dominant (V) chord, enhancing the overall harmonic flow. It helps maintain the traditional IV-V-I progression while introducing some variation.

Voice Leading

When employing the ii6 chord, careful attention must be paid to voice leading to avoid undesirable parallel octaves or fifths. To achieve smooth voice leading, it is recommended to move the upper voices in contrary motion with the bass. This technique ensures that the individual voices transition smoothly and maintains the integrity of the harmonic progression.

In conclusion, the prevalence of ii6 over ii in tonal music can be attributed to its strong harmonic function as a predominant chord, the distinct bass note in first inversion, its resemblance to the IV chord, the added color and smoother resolution it provides, and the importance of proper voice leading. By understanding the advantages of the ii6 chord, composers and musicians can make informed decisions when crafting harmonic progressions.

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FAQs

What is the difference between ii6 and ii chords?

The ii6 chord is in first inversion, with the third of the chord as the bass note. In contrast, the ii chord is in root position, with the root note as the bass. This inversion gives the ii6 chord a different sound and contributes to its unique harmonic function.

Why is the ii6 chord considered a strong predominant chord?

In tonal music, predominant chords serve as a transition from tonic function to dominant function. The ii6 chord is commonly used as a strong predominant chord due to its harmonic characteristics, which help create tension and prepare for the dominant chord.

How does the ii6 chord resemble the IV chord?

Inverting the ii chord to ii6 creates a chord voicing that shares common tones with the IV chord. The lowest note of the ii6 chord resembles the root and third of the IV chord, contributing to the tonal stability and familiarity of the progression.

What is the effect of using ii6 instead of ii in a progression?

Using ii6 instead of ii adds a minor color to the progression. The presence of the sixth in the ii6 chord creates a minor flavor, contrasting with the major quality of the other chords in the progression. Additionally, ii6 provides a smoother resolution to the dominant chord, enhancing the overall harmonic flow.

Why is voice leading important when using ii6?

Proper voice leading is crucial when using ii6 to avoid parallel octaves or fifths, which can result in undesirable harmonic effects. Moving the upper voices in contrary motion with the bass helps achieve smooth voice leading and ensures a coherent and pleasing harmonic progression.