Tritone Ear Training
The tritone — also called the "Devil's Interval" — is the most dissonant interval in Western music. At exactly six half-steps, it sits right in the middle of the octave and creates maximum tension.
What is a tritone?
A tritone (TT) is an interval spanning six half-steps (three whole tones — hence "tri-tone"). From C to F# is a tritone. It can also be called an augmented fourth or diminished fifth, depending on context.
It divides the octave exactly in half, which gives it a uniquely unstable, ambiguous quality.
Why is it called the Devil's Interval?
In the Middle Ages, the tritone was considered so dissonant that it was nicknamed diabolus in musica (the Devil in music). Singers were supposedly forbidden from using it in sacred music.
Today the tritone is used extensively in jazz, blues, and rock. The opening of "The Simpsons" theme and "Purple Haze" by Jimi Hendrix feature prominent tritones.
How to recognize a tritone
- It sounds tense, eerie, and "wrong" — like two notes fighting each other.
- It doesn't sound "bright" like a major interval or "dark" like a minor interval — it sounds unsettled.
- Compare it against the perfect fourth (5 half-steps) and perfect fifth (7 half-steps) to hear how the tritone is uniquely unstable.
- Once you learn to hear the tension, the tritone becomes one of the easiest intervals to identify.
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