A multiphonic harmonic on vibraphone

This video presents what seems to be an unreported multiphonic harmonic on the vibraphone. For the vibraphone, a common technique in contemporary literature features the isolation and production of a single harmonic (h04) in the lower octave. However, through experiments by Olaf Tzschoppe (DE) and Michael Edgerton (SE) on the vibraphone, an unreported multiphonic was found on the lowest thirteen bars on five different instruments in Bremen, Germany.
This unusual flageolet features multiple, perceptible tones produced from a single mallet strike with precise placement of a single, lightly touching finger. Compared to the isolated harmonic 4, during this unusual flageolet the right-hand strike and left-hand touch occur at different locations on the bar, though the left-hand pressure and velocity of strike are similar. In this paper we refer to this sound as a multiphonic harmonic.
The spectra of this multiphonic harmonic (Mph0) feature two main nonharmonic partials with amplitudes greater than the fundamental frequency (F0). The ratios of these two partials (px and py) to their F0, change as pitch goes up and down. Furthermore, these two main partials feature dynamic temporal envelopes, with px dominating during the attack, followed by py evolving to a prominent position in the sustain.
These issues are presented in an article titled, “On the acoustics of a multiphonic flageolet on the vibraphone”.
Olaf Tzschoppe. Professor of Percussion at University of the Arts Bremen, Germany
Michael Edgerton. Professor of Artistic Research at Lund University - Malmö Academy of Music.