The A Major Triad: A Music Theory Guide 🎶🎸🎹

By Jade Bultitude
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In this article you’ll learn how to construct the A major triad as well as how to play it on piano and guitar.

We’ve also included sections on inversions and figured bass for those that want a deeper understanding. Lastly, listen to some examples of popular songs that featured this triad.

Root , 3rd and 5th

The A major triad is formed of the 1st, flat 3rd and flat 5th of the A major scale.

  • A – root note
  • C# – Major 3rd above the root
  • E – perfect 5th above the root

Here is the triad written on the stave in the treble and bass clef.

A major chord treble clef
A major chord bass clef

Before you read on make sure that you have a basic understanding of intervals. Intervals are vital for understanding how triads are built. Check out our guide to major, minor and perfect intervals for more on this.

A Major Triad on Piano

Below you can see how to play this triad on the keyboard or piano. This pattern of notes could also be played starting on any A note.

However, the order of the notes must be the same:

  • A – lowest note
  • C sharp – middle note
  • E – highest note

This is called ‘root position’.

A maj triad root position piano diagram

A Maj Triad on Guitar

There are two simple positions that you can use to play a A major chord on guitar. Both positions can also be slide up or down the neck to play different major triads.

A maj triad, root position, guitar charts

1st Inversion

A 1st inversion is where we take a triad but we start on the second note, which in this case is C sharp. We still keep the E above, but then the A (or root) become the highest note.

This way of rearranging a triad gives us a different sound as the relative pitches of the three notes has changed.

  • C sharp – lowest note
  • E – middle note
  • A – highest note
A maj triad, 1st inversion

1st inversion on Piano

On the piano we can play the 1st inversion of an A Maj triad by starting on a C sharp. They play the E above and the A above this.

A maj triad 1st inversion, piano diagram

1st Inversion of Guitar

Below are the most common shapes for playing an A major chord in the 1st inversion. Remember that we can only use certain shapes are the pitches of the three notes are important.

A maj triad 1st inversion guitar charts

2nd Inversion

A 2nd inversion is where we take a triad but we start on the third note, which in this case is E natural. We still keep the A above this as we did from the 1st inversion. Then the C# becomes the highest note in the chord.

  • E – perfect 5th (lowest note)
  • A – root note (middle note)
  • C# – major 3rd (highest note)

We could construct a 2nd inversion starting on any E note in any octave. The only thing that must stay the same is that the we use the A above and the C# above that.

A maj triad 2nd inversion

How to play A major 2nd inversion on Piano

On the piano we can play the 2nd inversion of an A Major chord by starting on a E natural. They play the A above and the C# above this.

A major triad 2nd inverison piano diagram

2nd Inversion of Guitar

Below are the most common shapes for playing an A major triad in the 2nd inversion. Remember that we can only use certain shapes are the pitches of the three notes are important.

A major chord 2nd inversion guitar chart

Triads from the A Major Scale

By looking at the A Major scale we can actually make triads built on each note and only using notes from A major. Below you can see a list of each triad we will create be starting on different notes of the scale.

  • A Major
  • B Minor
  • C# Minor
  • D Major
  • E Major
  • F# Minor
  • G# Diminished
chords in a major

Famous Songs in A Major

Here’s 3 famous examples of songs in the key of A major. For this reason, they use A Major triads, as the root note chord, priminently in their chord progressions.

‘Wonderwall’ – Oasis

Oasis’ ‘Wonderwall,’ composed in the key of A major, is an iconic Britpop anthem that has resonated with audiences for decades. With its memorable acoustic guitar riff and evocative lyrics, this song has become a rock classic.

‘Boys Don’t Cry’ – The Cure

The Cure’s ‘Boys Don’t Cry,’ written in the key of A major, is a post-punk masterpiece that blends catchy melodies with melancholic themes.

‘Halo’ – Beyonce

Beyonce’s ‘Halo,’ composed in the key of A major, is a captivating R&B ballad known for its soaring vocals and emotional resonance. With its powerful melody and heartfelt lyrics, this song has become a standout in Beyoncé’s discography.

Figured Bass Notation

Figured bass is an alternative way of labelling chords. It uses vertical numbers to denote chords and it can be used to label any type of triad. Below are the figured bass symbols for the A Major chord in all three inversions. 

A major chords figured bass
  • Root Position – 3/5 indicates that a 3rd above the root and a 5th above the root are to be played.
  • 1st Inversion – 3/6 indicates that a 3rd and 6th should be played above the root note
  • 2nd inversion – 4/6 indicates that a 4th and 6th above the root note should be played.

There are also figured bass symbols for minor, diminished and augmented triads. A summary is below, but if you want a deepen explanation of how to use this notation, check out our complete guide to figured bass.

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AUTHOR
Jade is a flute player and music educator with a passion for educating the next generation of musicians. She is a Masters Graduate from Trinity Laban Conservatoire of Music and Dance. Jade has been helping people learn music theory for more than 10 years from pre school children all the way to degree level studies.