The goal of this work is to investigate experimentally the music intervals in modern Byzantine Chant performance and to compare the obtained results with the equal temperament scales introduced by the Patriarchal Music Committee (PMC). Current measurements resulted from pressure and electroglottographic recordings of 13 famous chanters singing scales of all the music genera. The scales' microintervals were derived after pitch detection based on autocorrelation, cepstrum, and harmonic product spectrum analysis. The microintervallic differences between the experimental values and the PMC's ones were statistically analyzed indicating large deviation of the mean values and the standard deviations. Significant interaction effects were identified among some genera and between ascending and descending scale directions.