Not a great deal, however, the false (or cross) relation of the Tritone (augmented fourth) and of the augmented or diminished octave must be avoided. The false relation occurs when the distance from the lower note of one interval to the upper note of the next interval (or the reverse) is an augmented fourth or an augmented or diminished octave. To avoid the false relation of the augmented fourth, never write in succession the major thirds on the fourth and fifth degrees of the scale.

R.