Review material below, then move to the next slide to practice your knowledge of chords with an interactive exercise.

Chords are sets of two or more notes played simultaneously.

You are free to repeat chord notes as many times as you like, and play chord notes in any order, when playing a chord.

In practice, most chords are built with thirds.

An interval is the distance between two notes.

A third is an interval that spans three letters.

When we say that a chord is built in thirds, we only care that chord notes are thirds apart when starting from the root note and listing the remaining notes in left-to-right order on the piano keyboard.

The major-scale-relative formula for major chords is: 1 3 5

The major-scale-relative formula for minor chords is: 1 3♭ 5

The major-scale-relative formula for diminished chords is: 1 3♭ 5♭

The major-scale-relative formula for dominant 7th chords is: 1 3 5 7♭