Cm7 Piano Chord

Piano Diagram of Cm7 in Root Position

Cm7 is a minor chord built on the key of C with an added minor 7th. It is formed by the notes C, Eb, G, and Bb. In this article, we’ll explore the music theory underlying the Cm7 chord, including its construction, common voicings, and its role in chord progressions.

 

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Finger Position

 

Cm7 Chord Inversions

 

The Cm7 chord has a total of 3 inversions:

Piano Keyboard Diagrams

Cm7 Chord Equivalencies

Rearranging the notes of a chord can result in unique and interesting chord equivalencies. This is particularly true for 7th chords, where we can create a distinct type of chord by rearranging the notes of a minor 7th chord in a specific way.

For instance, if we take the 1st inversion of a minor 7th chord, where the 3rd note becomes the root note, we end up with a major 6th chord (also known as an “add 6th” chord).

Let’s consider the Cm7 chord, which comprises the notes C, Eb, G, and Bb. If we rearrange the notes such that Eb becomes the root note, we obtain an Eb6 chord with the notes Eb, G, Bb, and C.

1st Inversion of Cm7 = Eb6

The reason why the 1st inversion of a minor 7th chord results in a major 6th chord is due to the note relationships between the chords. When we move the 3rd note to become the root note, we end up with a chord that features a major 3rd, perfect 5th, and a major 6th interval.

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Music Theory and Harmony of Cm7

 

In music theory, m7 chords, also known as minor seventh chords, are commonly used and have a melancholic or introspective quality. They can be found in various genres such as jazz, blues, pop, and classical music. These chords add richness and tension to a musical piece and are often used as tonic, subdominant, or dominant chords.

 

Building the Cm7 Chord: Different Approaches

When building a minor seventh (m7) chord, there are a few different approaches you can take. These approaches can be used interchangeably to construct m7 chords and provide different perspectives on building these chords:

Starting from the C Major Scale

C minor 7th is built by combining the Root, a minor 3rd, a 5th, and a minor 7th interval from a minor scale, however, for educational purposes, it may be clearer to demonstrate its construction using a major scale, as it better illustrates the relationship between intervals and their qualities.

For example, to build a Cm7 chord, you can start with the C Major scale, which consists of the notes C, D, E, F, G, A, and B.

 

 

To create a Cm7 chord, apply the formula R, m3, 5, m7 in the following manner:

1. Begin with the Root note, C.
2. Select the 3rd interval, which is E then lower it down by a half-step to get the minor 3rd Eb.
3. Include the 5th note, G.
4. Finally, add the minor 7th interval, Bb.

By following this simple formula, you can create a minor 7th chord from any major scale.

 

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by Combining Intervals

Another way to form a minor 7th chord is by combining specific intervals – a minor 3rd, a major 3rd, and another minor 3rd.

m3 + 3 + m3 = minor 7th Chords

If we observe the intervals between the notes, we can notice that C-Eb creates a minor 3rd interval, Eb-G forms a major 3rd interval, and G-Bb is a minor 3rd interval. By stacking these three intervals together, we can build the Cm7 chord.

 

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How to Use C min7 in a Chord Progression

 

The C minor 7th chord can have various harmonic functions, depending on its context within a piece of music. Here you can see on what degrees it appears naturally:

on Natural minor Scales

• Tonic chord in C minor
• Subdominant chord in G minor
• Dominant chord in F minor

 

on Major Scales

• Supertonic chord in Bb Major
• Mediant chord in Ab Major
• Submediant chord in Eb Major

 

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Cm7 Function in Major and Minor Keys

Understanding Scale Degrees

To understand the relationships between the notes in a scale and their functions within chords, it’s essential to know about scale degrees. The diatonic major scale is made up of seven degrees, each with its own unique role in creating the overall harmony of the scale.

1. Starting with the first degree of the scale, known as the Tonic, this note serves as the anchor for the music. It establishes a stable tonal center that acts as the foundation for the scale.
2. Moving on to the second degree, called the Supertonic, it’s often used as a transitional note between the Tonic and other notes in the scale. It creates a sense of motion within the melody or harmony.
3. The third degree of the scale is the Mediant, which sits halfway between the Tonic and Dominant notes. It helps establish whether the scale is major or minor.
4. The fourth degree, known as the Subdominant, is used to complement the Dominant and add tension and resolution to the music.
5. The fifth degree is the Dominant, which creates tension and anticipation within the melody or harmony. This note is typically resolved by returning to the Tonic.
6. The sixth degree, the Submediant, is often employed as a transitional note between the Dominant and Tonic, adding a sense of stability and restfulness to the music.
7. Finally, the seventh degree is the Leading tone, located one half-step below the Tonic. It creates a strong sense of tension and a desire to resolve to the Tonic. This note is frequently used to create a sense of resolution and finality in the melody or harmony.

 

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Cm7 as Tonic Chord in C Minor

In the key of C minor, Cm7 can serve as the Tonic chord. This means that it’s the chord that creates a sense of stability and resolution, acting as the starting point and tonal center of the scale.

 

Cm7 Chord Progressions as i degree

The following chord progressions are examples of how C minor 7th can serve as the tonic chord (i degree). I’ve added a possible voicing but it’s just a suggestion.

i VI VII III

 

Chromatic modulation

 

i iv VI VII

 

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Cm7 as Subdominant Chord in G Minor

C minor 7th can also appear as the subdominant chord (iv degree) in the key of G minor.

 

Cm7 Chord Progressions as iv degree

The following chord progressions feature a Cm7 chord as the subdominant (iv degree):

iv III VI VII

 

i iv VI v

 

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Cm7 as Dominant Chord in F minor

In F minor, Cm7 can be used as the dominant chord. As a dominant minor chord in a minor key, the Cm7 creates a sense of tension and anticipation, leading to the resolution of the tonic chord, which in this case is Fm.

 

Cm7 as v degree – Chord Progressions

If you want to hear how C minor 7th sounds as the dominant chord in F minor, try playing the following chord progressions:

i iv VI v

 

i v VI VII

 

i VI v iv

 

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Cm7 as Supertonic Chord in Bb Major

Although often associated with natural minor scales, Cm7 can also be used in major keys. In the key of Bb major, for example, Cm7 functions as the supertonic chord, which is located on the second degree of the scale.

In this context, Cm7 creates a slightly tense and unresolved sound, adding a feeling of anticipation or expectation as it typically leads to the dominant or subdominant chords.

 

Cm7 Chord Progressions as ii degree

Try playing the following chord progressions to better understand how the Cm7 chord functions as the supertonic (ii) chord in the key of Bb major.

ii V I

 

I IV ii V iii vi ii V

 

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Cm7 as Mediant Chord in Ab Major

Cm7 has yet another function apart from its positions in minor and major keys. It can also serve as the mediant (iii) chord in the key of Ab major, which is located on the third degree of the scale.

 

Cm7 Chord Progressions as iii degree

To better understand how Cm7 serves as the mediant in the Ab major scale, you can try playing the following chord progressions:

I iii IV V

 

I iii ii V

 

I iii vi IV

 

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Cm7 as Submediant Chord in Eb Major

You can play Cm7 on the sixth degree of the Eb major scale where it functions as the submediant chord. The submediant chord usually brings a sense of relaxation and stability to a chord progression.

 

Cm7 as vi degree – Chord Progressions

You can explore the sound of Cm7 as the submediant chord in the key of Eb major by playing the following chord progressions:

I iii vi V

 

I vi ii V

 

I IV ii V iii vi ii V

 

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Alternative Names for Cm7 Chord

• C-7
• Do -7
• Do m7
• Cm7th
• C min7
• Do min7
• C minor 7th
• C minor seventh

 

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Conclusion

The chord progressions and examples presented in this post provide a comprehensive overview of the most common uses of the Cmin7 chord. It’s important to note, however, that many advanced harmony-related topics could not be included due to space constraints. These topics include chord progressions built on harmonic and melodic scales, modal scales, hidden tonality, secondary dominants and other chord substitutions, non-functional harmony and atonal music, modal interchange and borrowed chords, voice leading and counterpoint, chromatisms, jazz harmony…I mean, music theory is a huge topic!

Although I couldn’t cover all of these topics in my post, I encourage readers to continue exploring these areas in their own study and research. By expanding your knowledge in these advanced areas of music theory, you can gain a deeper understanding of the harmonic possibilities that exist beyond the basics presented here.