Chord quality by ear

Once you can name a chord’s quality by ear, you can follow a song without sheet music, work out a cover by listening, and check whether the chord you just played on your own instrument is the one you meant to play. That skill carries over into playing and writing music more directly than almost anything else you can practice.

The four qualities in this exercise all share the same skeleton — a root, a third, and a fifth — and nearly all of the character comes from one interval: the third above the root.

• A major third (4 semitones) sounds bright and settled — that’s a major chord.
• Shrink it by one semitone to a minor third (3 semitones) and the same shape turns dark and inward — that’s a minor chord.
• A diminished chord takes that minor third and squeezes the fifth down as well, so it sounds anxious, like it wants to resolve somewhere else.
• An augmented chord takes a major third and stretches the fifth up instead, so it sounds suspended and unresolved in the opposite direction.

To train your ear, sing the third above the root you hear, quietly or in your head, and compare it to a chord you already know is major or minor. If your hum feels close to “happy,” you’re probably hearing a major third; if it feels close to “sad” or “uneasy,” a minor one.

The exercise below plays a chord and asks you to name its quality. Answer wrong, and it tells you which chord you actually heard, so you always know the right answer before you try the next one.