Why does the C7 chord contain a flattened 7th instead of the real 7th note?
Why Does the C7 Chord Contain a Flattened 7th Instead of the Real 7th Note?
The C7 chord is a dominant 7th chord that consists of the notes C, E, G, and B-flat (C-E-G-B♭). It is a common chord in many musical styles and is known for its rich and vibrant sound. However, a question arises: Why does the dominant chord contain a flattened 7th while this tone is not even in the scale? In this article, we will explore the reasons behind the inclusion of a flattened 7th in the dominant chord and its role in creating musical tension and resolution.
The Role of Tension and Resolution
One of the fundamental principles of music is the concept of tension and resolution. Tension creates a sense of instability or unease, while resolution provides a sense of stability and rest. The dominant chord, with its flattened 7th, plays a crucial role in this interplay between tension and resolution.
The flattened 7th in the dominant chord creates a dissonant interval with the root note. Dissonance is an essential element of music that adds complexity and interest. This dissonance creates tension that naturally seeks resolution. In the case of the dominant chord, the flattened 7th wants to resolve down by a half step to the 3rd of the tonic chord.
The Resolution to the Tonic Chord
The flattened 7th in the dominant chord needs to resolve to the tonic chord, which is why it is in the scale of the resolving key. In the key of C major, the dominant chord is G7 (G-B-D-F). The F in the G7 chord is the flattened 7th, and it resolves down to the E in the C major chord (C-E-G). This resolution creates a sense of closure and stability in the music.
Understanding the Dominant 7th Chord
To understand why the dominant chord contains a flattened 7th, we need to look at its construction. The dominant 7th chord has an extra note compared to the triad of the 1st, 3rd, and 5th. In the case of C7, the sequence is followed, so it’s a 7, but it’s not the 7th note of the C major scale.
The dominant 7th chord is built off the dominant note of the scale, which is the 5th note. In the key of C major, the dominant note is G. To construct a G7 chord, we stack the next three notes above G, which are the 7th (F), 9th (A), and 11th (C) of the C major scale. This construction gives us the G7 chord (G-B-D-F).
Conclusion
In conclusion, the inclusion of a flattened 7th in the dominant chord, such as C7, is essential for creating tension and leading to the resolving chord. The flattened 7th creates dissonance and seeks resolution to the tonic chord, providing a sense of closure and stability in the music. Understanding the construction and function of the dominant 7th chord helps us appreciate its unique role in music theory and composition.
Sources:
- Quora: Why does the dominant chord contain a flattened 7th while this tone is not even in the scale?
- Music: Practice & Theory Stack Exchange: Why does the dominant chord contain a flattened 7th?
- Classical Guitar Delcamp Forum: Dominant 7th chords
FAQs
What is the C7 chord, and why does it contain a flattened 7th?
The C7 chord is a dominant 7th chord consisting of the notes C, E, G, and B-flat. The flattened 7th, represented by B-flat, creates tension and adds dissonance to the chord, which resolves to the tonic chord.
Why is the flattened 7th included in the dominant chord when it is not part of the C major scale?
The flattened 7th in the C7 chord is not derived from the C major scale. Instead, it comes from the scale of the resolving key, where the dominant chord typically leads. In the key of C major, the dominant chord is G7, which contains the flattened 7th (F) that resolves to the tonic (C) in a satisfying way.
How does the flattened 7th contribute to the tension and resolution in the C7 chord?
The flattened 7th in the C7 chord creates dissonance and instability, generating tension in the music. This dissonance seeks resolution by moving down a half step to the 3rd of the tonic chord, creating a sense of release and stability.
Can the C7 chord be used in different musical contexts?
Yes, the C7 chord is widely used in various musical genres, including jazz, blues, and pop. Its distinctive sound and function as a dominant chord make it a versatile choice for adding tension and leading to resolving chords.
Are there other variations of the dominant 7th chord besides C7?
Yes, there are dominant 7th chords in every key. The dominant 7th chord is built off the fifth note of the scale, and its construction follows the same pattern as C7. For example, in the key of G major, the dominant 7th chord is D7 (D-F#-A-C).
Can the C7 chord be substituted with other chords?
Substituting chords is common in music. The C7 chord can be substituted with other dominant chords, such as C9 or C13, which add additional tensions and color to the chord progression. These substitutions can create different harmonic flavors and variations in the overall sound.
How can I incorporate the C7 chord into my guitar playing?
The C7 chord is a fundamental chord in many guitar styles. To incorporate it into your playing, you can practice strumming patterns or fingerstyle techniques that involve the C7 chord. Additionally, learning common chord progressions that include the C7 chord will help you apply it in various musical contexts.
What are some songs that prominently feature the C7 chord?
The C7 chord is featured in numerous songs across different genres. Some popular examples include “Hound Dog” by Elvis Presley, “Kansas City” by Wilbert Harrison, and “Stormy Monday” by T-Bone Walker. Exploring these songs can provide practical examples of how the C7 chord is used in real music.