Just to tell you that it is not a throat vibrato as someone claimed. After 50 years playing I know that for sure. No one of my muscles are moving here. So I measured with a spectrum analyzer a cycle time of this sound and it was 0,0478 sec. So the frequency is 21,27 Hz. Note that I can't change the frequency like in throat vibrato. Using here Bb harmonica 2nd hole drew is F and its basic frequency is 349,2 Hz. The frequency of sub contra F (4 octave lower) is 21,83 Hz. So taking into a count possible small error in my measurements, I claim that I get the reed vibrating in addition to its nominal frequency also 4th sub harmonic frequency, and that makes the "Maras vibrating sound". Note also that when I am bending the note lower the vibrato stands the same because its frequency depends only of the tuning of the reed, mara
