Melody and harmony: intervals, chords and cadences

In this guide we will look at a range of key musical concepts relating to melody and harmony, including:

• intervals and diatonic intervals

• chords

• dominant 7th

• diminished triad

• diminished 7th

• added 6th

• perfect, imperfect, plagal and interrupted cadences

• Tierce de Picardie

In music, an interval is the distance between two notes.

In the example below, count up from and including the lowest note up to the highest pitched note to identify the interval.

This interval is called a fifth. Try to play this interval on a keyboard or piano.

This example of an interval in the bass clef is a third

A chord is a group of notes - usually three or more - which are stacked vertically. They are played together and combine in harmony.

In western music, most chords are triads:

• the lowest note is the root
• the middle note is the third
• the highest note is the fifth

Just like notes, chords are numbered, to show the position of the note relative to its scale. Chords are numbered in Roman numerals.

For example, in the scale of C major, the chords are numbered like this:

• I - C major (notes are C, E and G)
• II - D minor (notes are D, F and A)
• III - E minor (notes are E, G and B)
• IV - F major (notes are F, A and C)
• V - G major (notes are G, B and D)
• VI - A minor (notes are A, C and E)
• VII - B diminished (notes are B, D and F)

An added 6th is a major triad with the addition of a 6th note above the root.

In this example you will hear both the notes of the chord and the chord played separately. You can follow along with the notation below.

A diminished triad is built on the 7th note of the scale.

Three are three semitones between consecutive notes.

In this example you will here both the chord and the notes of the chord played separately. You can follow along with the notation below.

In the track Remedy by Little Boots, the bass line outlines a diminished triad.

A diminished 7th is built on the 7th note of the scale.

There are three semitones between consecutive notes.

In this example you will hear both the notes of the chord and the chord played separately. You can follow along with the notation below.

In this extract from Die Stadt by Schubert, the only chord played by the piano is a diminished 7th.

A dominant 7th is built on the dominant note. It functions as a type of chord V.

In this example you will hear both chord I of C Major, and the dominant 7th chord. You can follow along with the notation below.

At the start of David Bowie's song Let's Dance you can hear a dominant 7th chord being built up.

A cadence is a sequence of notes or chords which comes at the end of a musical phrase.

As the cadence come at the end of a piece of music, different kinds of cadences will give the listener a variety of impressions as to how 'finished' the music sounds.

Below are the specifics of a range of different cadences. You should already know about perfect and imperfect cadences from the National 5 course.

A perfect cadence moves from chord V (dominant) to chord I (tonic) at the end of a phrase. It sounds finished.

Listen to this example of a perfect cadence and follow along with the notation below.

Look closely at that notation for music you are currently performing. Can you identify any perfect cadences?

What is an imperfect cadence?

The last chord at the end of a phrase is V. It sounds unfinished.

This example uses IV-V.

Listen to this example of an imperfect cadence and follow along with the notation below.

A plagal cadence moves from chord IV (subdominant) to chord I (tonic) at the end of a phrase. It sounds finished.

The plagal cadence is often remembered and identified by its distinctive Amen sound and is often used at the end of a hymn tune.

Hozier used the plagal cadence in the "amen section" of their song Take Me to Church.

Notice also:

• modulation from minor key (E minor) to the relative key of G major
• the use of melismatic singing in the word amen.

Listen to this example of a plagal cadence and follow along with the notation below.

• Listen to the a cappella introduction to Seven Bridges Road by the Eagles. Play along with this chord progression (D-C-G-D) which finishes each time on a plagal cadence.

• Listen to Let it Be by the Beatles and you will hear a plagal cadence on the words ' let it be'. Again, play along on a chordal instrument and focus on the sound of the plagal cadence.

An interrupted cadence moves from chord V to chord VI at the end of a phrase. It interrupts the flow of the music and sounds unfinished.

Listen to this example of an interrupted cadence and follow along with the notation below.