Vibrato Analysis in Byzantine Music

In this work we study the vibrato rate, extent and intonation in Byzantine Music. Two methods of analysis have been applied: the first based on the analytical signal and the second on the crests and troughs of the waveform of the vibrato signal. Tones samples were extracted from ascending and descending music scales, chanted by five famous singers for all the Greek vowels. The two analysis methods produced identical results in the level of significance, a=0.05, concerning the mean extent, the mean standard deviation of the rate and the mean intonation, while they differed in the rate (1.9-6.6%), the mean standard deviation of the extent (4-6 cents) and the standard deviation of intonation (0.46-1.20 Hz). Typical values of the average rate within a tone were found to be 5.35 Hz (SD: 0.96 Hz) and 5.13 Hz (SD: 0.95 Hz), while the most frequent values were 4.8 Hz and 4.5 Hz, for the first and second method, respectively. The average extent within a tone was 50 cents (SD: 18 cents). Moreover, the dependence of the vibrato parameters on pitch and sound intensity has been studied; there was no systematic relationship between them.