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Hints for Spelling Tritones: (Augmented Fourths and Diminished Fifths) |
| The tritone refers to both augmented fourths and diminished fifths. These intervals both contain exactly 6 half steps, and therefore cut the octave exactly in half. |
| If you remain on the white keys (no accidentals) then all the fourths and fifths are perfect except for the fourth from F up to B which is augmented, and the fifth from B up to F, which is diminished. Therefore, unless the interval involves both B and F, it is a perfect interval. |
| Look at the piano keyboard. Notice that the fifth from b to f is the only fifth that contains both natural half steps (b-c and e-f), and the fourth from f to b is the only fourth that doesn't contain any natural half steps. Those fifths with one half step and three whole steps (total of 7 half steps) are perfect fifths. Those with one half step and two whole steps (total of 5 half steps) are perfect fourths. Those that add up to 6 half steps are either augmented fourths (three whole steps) or diminished fifths (two whole steps and 2 half steps). |
| Sharps move a note up, flats move it down. Always think in terms of moving towards or away from the other note. Moving the upper note up makes a larger interval, while moving the lower note up makes a smaller interval. Moving both notes in the same direction doesn't change the interval. |
| The tritone will always occur naturally between the fourth and seventh scale degrees in any major key. In C major F is the fourth scale degree (subdominant), and B is the seventh scale degree (leading tone), therefore the tritone in C major is found as the augmented fourth from F to B, or the diminished fifth from B to F. |