Two types of violin vibrato on stopped and open string are compared by analysing with Super-Resolution Spectrogram. The term ’vibrato’ basically refers to the one applied on stopped string. However, violinists use vibrato even as playing on open strings. The analysis showed some clues to find the differences between them.
Stopped vibrato apparently has amplitude modulation which appears on almost all of the peaks, harmonics of bowed note. On the other hand, open vibrato has small amplitude modulation which appears on especially 2nd peak. There were the effects of vibrato not only on open G-string ,which has been proved in past studies, but also other open strings. In addition, small amplitude modulation on 1st, 2nd, and 6th peaks which refer to the same as bowed note when open vibrato is used at just octave above the bowed string, and the sinusoidal shapes of amplitude modulation are almost following the shape of 1st peak when open vibrato is used at the same as bowed note or harmonic of bowed note.