Chords. Triads and their inversions
Music Theory

Chords. Triads and their inversions

How are chords built – what does the accompaniment of a song consist of?

A chord is a combination of three or more sounds at the same time. There is a nuance: these sounds must be arranged in thirds (in the vast majority of cases), or they can be arranged in thirds. Remember the article ” Inverting intervals “? With chords, you can do the same tricks (move the notes of a chord according to certain rules), which is why the amendment “can be arranged by thirds” is used.

The sounds of the chord line up from the bottom up. Let’s consider chords consisting of three sounds:


A chord that consists of three sounds is called a triad . Depending on which thirds are involved in the construction of the triad, and also depending on the order of the thirds, we get one or another type of triad. From major and minor thirds , 4 types of triads are obtained:

  • The major triad consists of b.3 and m.3 . Such a triad is also called “big”. Between its extreme sounds , part 5 (consonant interval).
Major triad

Figure 1. 1 – minor third, 2 – major third, 3 – perfect fifth.

  • The minor triad consists of m.3 and b.3. Such a triad is also called “small”. Between the extreme sounds of the chord , part 5 (consonant interval).
minor triad

Figure 2. 1 – major third, 2 – minor third, 3 – perfect fifth.

  • The augmented triad consists of b.3 and b.3. Between extreme sounds uv.5 (dissonant interval).
Augmented triad

Figure 3. 1 – major third, 2 – major third, 3 – augmented fifth.

  • A diminished triad consists of m.3 and m.3. Between extreme sounds um.5 (dissonant interval).
Diminished triad

Figure 4.: 1 – minor third, 2 – minor third, 3 – diminished fifth.

All three intervals of the major and minor triad are consonant. These triads are consonants. In augmented and diminished triads there are dissonant intervals (up.5 and down.5). These triads are dissonant.

All three sounds of the triad have their own names (from bottom to top): prima, third, fifth. It can be seen that the name of each sound coincides with the name of the interval from the lower sound to itself (the sound in question).

Triad inversion

The arrangement of sounds in the order of prima-tertium-fifth (from bottom to top) is called basic . In this case, the sounds of the triad are arranged in thirds. If the order of the sounds changes so that the lower sound becomes a third or a fifth, then this position of the sounds is called “reversal”. Like the intervals.

  • Sextachord . This is the first type of triad reversal, when the prima is moved up an octave. Indicated by the number 6.
  • Quartsextachcord . The second type of conversion is when the prima and third are transferred up an octave. Indicated by ( Quartsextachcord).
Fixing the material

Finally, we propose to fix the material. Press the key of our piano, the program will build a triad from the note you have chosen.



We want to pay attention to the following point: the sounds of the considered triads are arranged in thirds . One of the visitors had a question: “Why is the triad composed of the I, III and V steps of the mode?”. Sounds are located primarily on thirds. If you build a chord not from the first step (we are running ahead), then other steps of the mode will be involved.


Now you know how to build various triads and their inversions.

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