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Learn music theory with Sonid - Part 7 - Perfect Fourth

Today's topic: "What is a perfect fourth?" In this video you will learn how to construct and identify a perfect fourth interval in 30 seconds. Including some examples and common mistakes.

An interval is the distance between two notes. To identify an interval you must:

  • 1 (number) - count the amount of naturals
  • 2 (quality) - count the semitone steps

In music theory, a fourth (perfect, diminished or augmented) is the interval between a natural and the fourth one above it. For example, the interval between tones C and F is a second, but the interval between F and B is as well.

Additionally, a perfect fourth consists of 5 semitones and is abbreviated with P4.

Common mistakes are often made when the notes of an interval use different naturals, but musically sound the same. An example of this would be a C to a E sharp. Or F to A sharp. Which are both different intervals, but sound like a perfect fourth.

This may sound a little confusing at first, and it probably is. But when advancing in music theory it is an essential skill to understand. With it, you will be able to create chords, scales and progressions.

So, to correctly construct or identify a perfect fourth make sure that you count four naturals. And there are five semitones between the notes.

That's it, you can now use the perfect fourth!