What is a Tritone?

The tritone was considered to be a forbidden interval hundreds of years ago. Churches actually banned this interval from being played! Luckily there are no such restrictions today so we will be experimenting with it and understanding what its function is.

To put it very simply, the tritone is half an octave. There are twelve possible tones in Western music and if you go six half steps you will create a tritone. When you invert a tritone, it remains a tritone because it divides the octave exactly in half. When you play a triton you will understand why it was feared; the sound is eerie and almost demonic. In fact, it is used extensively in heavy metal music!

How does a tritone resolve? This is a very interesting aspect to tritones because you can go outward or inward by half steps and the tritone will resolve either way. So, if you have a tritone C – F-sharp, it could resolve outward to B – G. Or, it could resolve inward by half steps to C-sharp – E-sharp. Interestingly, each of these resolutions (outward or inward) end up being a tritone apart from one another. When resolving outward we ended up in G and when resolving inward it resolved to C-sharp. (G and C-sharp a tritone apart!)

The tritone is actually the basis for all Western music. This is because it is very important in determining the key of your music. In the classic cadence, I – IV – I 6/4 – V7 I, it is the tritone of the V7 chord that establishes the key.

A diminished 7th chord is actually two tritones creating great tension and a myriad of possibly resolutions which you can explore in the following videos:

Thanks again for joining me Robert Estrin Robert@LivingPianos.com