What Is a Chord?

A chord is any combination of three or more notes played simultaneously. Chords form the harmonic backbone of music — they determine the emotional "color" of a song. Understanding chord theory lets you write better music, play by ear, and understand what you're hearing.

The Four Basic Triad Types

A triad is a three-note chord built by stacking intervals of thirds. The formula is measured in semitones from the root note.

Major Chord (0 – 4 – 7)

Root + Major 3rd + Perfect 5th. Example: C Major = C + E + G. Major chords have a bright, happy, open quality. They're the foundation of countless pop and classical pieces.

Minor Chord (0 – 3 – 7)

Root + Minor 3rd + Perfect 5th. Example: A Minor = A + C + E. The only difference from major is that the middle note drops by one semitone. Yet that one semitone completely changes the emotion — minor chords sound sad, introspective, or dramatic.

Augmented Chord (0 – 4 – 8)

Root + Major 3rd + Augmented 5th. Example: C Augmented = C + E + G#. Augmented chords are tense and ambiguous. They create a sense of instability — a longing to resolve to another chord.

Diminished Chord (0 – 3 – 6)

Root + Minor 3rd + Diminished 5th. Example: B Diminished = B + D + F. Highly dissonant and dark. Diminished chords appear in classical music at dramatic moments and in jazz as passing chords.

Chord Inversions

The same chord notes can be arranged in different orders, called inversions:

  • Root position: Root on the bottom (C–E–G)
  • First inversion: 3rd on the bottom (E–G–C)
  • Second inversion: 5th on the bottom (G–C–E)

Inversions give chord progressions smoother voice leading — notes move shorter distances between chords.

Seventh Chords

Add a fourth note (a 7th above the root) to create seventh chords, which add richness and sophistication:

  • Dominant 7 (e.g., G7): Major triad + minor 7th. The quintessential blues and jazz chord, full of tension.
  • Major 7 (e.g., Cmaj7): Major triad + major 7th. Dreamy, floating, used in bossa nova and jazz.
  • Minor 7 (e.g., Am7): Minor triad + minor 7th. Melancholic and smooth, common in R&B and soul.
  • Half-Diminished (m7♭5): Diminished triad + minor 7th. Dark and jazz-flavored.

How to Recognize Chords by Ear

Build ear recognition progressively:

  1. Master major vs. minor (this alone changes everything)
  2. Add augmented — notice the unresolved, tense sound
  3. Add diminished — the darkest, most unstable sound
  4. Practice dominant 7th — feel how much it "wants" to resolve
  5. Use BeMaestro's Chord Recognition module daily for 5–10 minutes

BeMaestro for Chord Training

BeMaestro plays a random chord and asks you to identify it — major, minor, augmented, or diminished. Immediate audio feedback, difficulty progression, and streak tracking make it the most engaging chord ear training tool available.

Conclusion

Chord theory is the grammar of musical language. Once you understand the major/minor/augmented/diminished framework and can hear the differences, you'll unlock the ability to play by ear, compose confidently, and understand any piece of music. Download BeMaestro and start recognizing chords today!