One of the most important sounds you can train your ear to recognize. Perfect fifths are important because they’re stable, open, and show up constantly in real music, which makes them a reliable reference point for hearing harmony and melody. As you listen, pay attention to how clean and grounded the interval feels, there’s no tension, just strength and space. You’ll hear perfect fifths in bass lines, melodies, power chords, and even in how instruments are tuned, so once your ear locks into this sound, you’ll start noticing it everywhere.

May the force be with you, always.

In part II of dominant 7ths, we’re focusing on dominant 7th chords within a ii-V7-I progression, one of the most important progressions to recognize by ear. The dominant 7th is what creates the strongest tension in the progression, pulling the harmony forward and clearly pointing back to the home chord. As you listen, pay attention to that unstable, “almost there” feeling in the V7 and how satisfying it is when it finally resolves to the I chord. You’ll hear this sound constantly in jazz, R&B, gospel, pop, and classical music, and once you can hear it, identifying keys and chord movement becomes much easier.

The dominant 7th creates strong tension that pulls the harmony away from home and then back again, making the resolution to the I chord feel especially clear and satisfying. As you listen, pay attention to how the V7 feels unstable and how obvious the return to the tonic sounds when it resolves. You’ll hear this cadence all over music, in endings, cadences, and key-defining moments, being able to recognize it will make identifying tonal centers much easier.

Perfect fourths are important because they’re stable but slightly more active than perfect fifths, showing up constantly in melodies and harmonic movement. As you listen, notice how the interval feels strong but a little more directional, like it wants to move somewhere. You’ll hear perfect fourths all over real music, in melodies, bass lines, chord movement, and common progressions and once your ear locks into that sound, it becomes much easier to recognize how music is moving.

One of the most important intervals for hearing harmony and chord quality. Major thirds are what give music brightness, light and open sound, and they’re a key part of major chords and melodies. As you listen, pay attention to the warm, uplifting feel of the interval and how it immediately suggests a major sound. You’ll hear major thirds everywhere, in melodies, chord progressions, harmonies, and riffs and once your ear locks into this interval, it becomes much easier to recognize major chords in real music.

Minor thirds are a "load-bearing interval", they are crucial because they define the sound of minor chords and provide an emotional quality. As you listen, pay attention to the slightly sad, tense, or introspective feel of the interval and how it immediately suggests a minor sound. You’ll hear minor thirds everywhere , in melodies, chord progressions, riffs, and vocal lines   and once your ear locks into this interval, it becomes much easier to recognize minor harmony in real music.