Seventh Chords
Let’s look at how to play an A7 chord on the piano. We’ll also learn the pattern for building any seventh chord.
What Are Seventh Chords?
Seventh chords are major chords with an added note. The added note is the seventh note of the matching major scale, lowered 1/2 step.
So to build a seventh chord, we’ll start by building a major chord. Major chords are built using the first, third and fifth notes of the matching major scale (learn how to build a major scale here).
To convert the major chord into a seventh chord, we’ll find the seventh note of the matching major scale and lower it 1/2 step.
How to Play an A7 Chord
Now let’s build an A7 chord on the piano. First we’ll build our A major chord using the first, third and fifth notes of the A major scale: A – C♯ – E.
Then we’ll find the seventh note of the A major scale, G♯, and lower it 1/2 step to G.
So to play an A7 chord, we’ll play:
A – C♯ – E – G

You can use this pattern to build any seventh chord. First build a major chord. Then find the seventh note of the matching major scale and lower it 1/2 step.
Other Chord Types
There are many other chord types you can learn. Here are some others:
Major
Minor
Augmented
Diminished
Second
Minor Second
Suspended
Fifth
Sixth
Minor Sixth
Minor Seventh
Major Seventh
Ninth
Minor Ninth
Major Ninth
Conclusion
Now you know how to build an A7 chord on the piano, and you can use that knowledge to build any other seventh chord!
Using patterns on the piano to build chords and to play creatively is a wonderful way to learn and enjoy the piano!
Hi we sometimes read about the dominant note, for example, C dominant 7. could you please explain what they are? Thanks a lot.
Yes, a C dominant 7 chord is the same as a C7 chord (C – E – G – B♭). The reason it may be called “dominant seventh” is because the notes of a major scale can be labeled using these names: tonic, supertonic, mediant, subdominant, dominant, submediant, leading tone, tonic. In the key of F major, C is the dominant note (F, G, A, B♭, C, D, E, F). A C major chord could also be called the dominant chord for the key of F major. Sometimes a dominant chord in a major key is converted into a dominant seventh, where an interval of a minor seventh is added above the root note of the chord, and then it can be called a “dominant seventh” chord. I hope that makes sense!
thanks a lot. but i also have another question to ask.Please forgive me for asking too many questions. The A major triad is as you know is A- C#- E. What is G-C#-E then? If it is the 2nd inversion then the major A and its 2nd inversion sound vastly different to my ear!!
No worries! Yes, the A major chord is A – C♯ – E. When the notes are played in that order, the A major chord is in root position (because the root note A – the note the chord is named after – is at the bottom of the chord). Inversions are when we rearrange the notes of the chord so the root is not at the bottom. If we move A to the top of the chord, the notes would be in this order: C♯ – E – A, which is first inversion. If we moved the C♯ to the top of the chord, the notes would be in this order: E – A – C♯, which is second inversion.
I lost my comment, sorry. This is how the internet is in this country!! I write again. the A major triad which is A-C#-E sound very different to its 2nd inversion G-C#-E. Why is this. Thanks for your time and efforts.
An A major chord is A – C♯ – E, and an A7 chord is an A major chord with the added G: A – C♯ – E – G. Since this chord has four notes, there are four positions this chord can be played in: A – C♯ – E – G is root position. C♯ – E – G – A is first inversion. E – G – A – C♯ is second inversion. G – A – C♯ – E is third inversion. I hope that helps!