Unraveling the Music Theory: What Does ‘7’ Mean After An ‘A’ Chord?

Journey through the rich world of music theory as we explain “What does 7 mean after an ‘A’ chord?” Discover the mystery and beauty behind the A7 chord and its integral role in the magical realm of sound.

Image of an electric guitar

Introduction: The Heart of Music Lies in Its Chords

Music, in all its forms, is a symphony of sounds, melodies, and harmonies that collectively touch the soul. A key component of this harmony lies in chords, and understanding them is akin to deciphering the complex language of music. One such mystery that often perplexes budding musicians is, “What does ‘7’ mean after an ‘A’ chord?”

Well, fret not! We are about to delve into the depths of music theory to unwrap the enigma behind this concept, explaining the A7 chord in its entirety.

What Does ‘7’ Mean After an ‘A’ Chord?

The world of chords is more than just a cluster of notes strummed together. When you see a ‘7’ after an ‘A’ chord, it’s not there by accident. It’s an indication of a specific type of chord, one that has shaped countless songs across genres: the A7 chord.

The ‘7’, often referred to as the ‘dominant 7th’, is a note added to a chord that essentially transforms the chord’s character, giving it a unique tonal flavor. In the case of an ‘A’ chord, the ‘7’ points towards the addition of a ‘G’ note (which is a ‘dominant 7th’ in the ‘A’ scale) to the original ‘A’, ‘C#’, and ‘E’ notes, thus forming the ‘A7’ chord. This A7 chord is a common addition in Blues and Jazz, known for its slightly dissonant and unresolved sound that creates a compelling need for musical resolution.

Exploring the Origins of the A7 Chord

The Emergence of Seventh Chords

Before we delve further into the anatomy of an A7 chord, let’s take a short detour into the realm of seventh chords’ history. These chords, with their distinctive dissonant character, have been a cornerstone in the music world since the Baroque period. However, their widespread usage gained prominence during the Classical and Romantic periods, where composers used them as dramatic tools in their symphonic works.

A7 guitar chord

The Jazz and Blues Influence

The introduction of Blues and Jazz in the 19th and early 20th centuries catapulted the seventh chords into a whole new level of popularity. Musicians started using the dominant seventh chord, including the A7, extensively in their compositions to add a touch of tension and create a sense of longing for resolution, thus enriching the emotional palette of these music genres.

Understanding the Science Behind the A7 Chord

The Music Theory of the A7 Chord

In music theory, the ‘A7’ is termed as a dominant seventh chord, constructed by adding a minor seventh to a major triad. The term ‘dominant’ here refers to the fifth degree of a diatonic scale, called the ‘dominant’. In this case, ‘A’ being the dominant of ‘D’, the ‘A7’ chord becomes the dominant seventh of the ‘D’ scale.

The Construction of the A7 Chord

For the A7 chord, we begin with the A Major triad, which includes the notes ‘A’ (the root), ‘C#’ (the major third), and ‘E’ (the perfect fifth).

To this, we add the ‘G’ note, which is the minor seventh in the ‘A’ major scale. The resulting ‘A’, ‘C#’, ‘E’, and ‘G’ notes played together give us the distinctive sound of the A7 chord.

How to Play the A7 Chord on Different Instruments

Strumming the A7 on a Guitar

On a guitar, the A7 chord is played by pressing the second fret of the fourth string (D string) to get the ‘E’ note and the second fret of the second string (B string) to get the ‘C#’ note. The other strings are played open to get the ‘A’, ‘E’, and ‘G’ notes.

Tickling the A7 on a Piano

On a piano, the A7 chord is played by pressing the ‘A’, ‘C#’, ‘E’, and ‘G’ keys together. It’s easy to locate these keys once you familiarize yourself with the piano’s layout.

The Emotional Impact of the A7 Chord

The A7 chord, with its dissonant quality, plays a pivotal role in evoking strong emotions in music. It creates a sense of tension and anticipation, thus drawing in the listener. This chord is also commonly used as a transitional tool leading to a resolution, intensifying the emotional impact of the music.

The Influence of the A7 Chord in Popular Music

The A7 chord’s unique sound has led to its usage in countless famous songs. From the Beatles’ “I Saw Her Standing There” to Robert Johnson’s blues classic “Cross Road Blues”, the A7 has enriched the soundscapes of many iconic tracks.

Conclusion: The Enigmatic A7 Chord Unveiled

Understanding what ‘7’ means after an ‘A’ chord is more than just a lesson in music theory. It’s a glimpse into the rich tapestry of sounds and emotions that chords weave in music. The A7 chord, in all its dissonant glory, is a testament to the incredible diversity and depth of music.


  1. What does ‘7’ mean in any chord, not just an ‘A’ chord?
    The ‘7’ in any chord refers to the addition of a seventh note to a major or minor triad, forming a seventh chord. This seventh note introduces a dissonant quality, adding depth and complexity to the music.
  2. What is the difference between an ‘A’ chord and an ‘A7’ chord?
    An ‘A’ chord is a major triad, consisting of the root note ‘A’, major third ‘C#’, and perfect fifth ‘E’. An ‘A7’ chord adds a minor seventh note ‘G’ to this triad, introducing a distinctive tonal characteristic.
  3. Why is the A7 chord popular in Blues and Jazz?
    The A7 chord’s dissonant and unresolved sound creates a compelling need for musical resolution, which is a characteristic feature of Blues and Jazz music.
  4. What’s the best way to practice playing the A7 chord?
    Practicing with a metronome and playing along with songs that feature the A7 chord can help you become comfortable with its sound and finger placement.
  5. Are there variations to the A7 chord?
    Yes, there are several variations of the A7 chord, including A7sus4, A7b5, and A9, each adding different notes or modifying the positions of the existing ones for a different sound.
  6. Can I use the A7 chord in any music genre?
    Absolutely! While the A

7 chord is particularly popular in Blues and Jazz, its unique sound can enrich compositions across all music genres.

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