The tritone and its resolution

The interval of #4 formed between the 4th and the 7th note is called the tritone in a major scale. Its name is due to the distance of 3 tones between both notes, whether in one or in the other direction:

4 – 7 or 7 – 4. In the key of C it is either F-B or B-F.

This interval has the feature of provoking great tension, since the said notes lie half a tone away from the two main notes of the scale (the tonic and the 3). The passing of this musical tension to the resting state is called resolution.

The resolution of the tritone will then be by means of a semitone descending from the 4 to the 3, and ascending from the 7 to the tonic, thus resolving the tension and creating a feeling of rest or stability.

Tensions generated by the tritone will be a key element to understand future topics.

The tritone and its resolution

The tritone

The dominant chord

The tritone will be the characteristic interval of a dominant chord (V7 or VIIm7b 5), V7 being the most frequently used. In this case, where the tritone resolves from the dominant chord of V degree to the tonic, we shall speak of the dominant resolving by a fourth leap (G-C), which is the distance between the fundamentals of the chords.

We can see that the notes of the tritone correspond to the 3 and the b7 of the dominant chord: the 3 will resolve to the tonic and the b7 to the third.

In harmonic analysis, resolution of a dominant chord by a fourth leap will be marked with an arrow going from that dominant chord to the resolution chord.

the tritone