Experimental analysis of non-periodic sound regimes in flute-like musical instruments.

Self-sustained musical instruments are complex nonlinear dynamical systems that are known to produce a wealth of dynamical regimes. This includes different kinds of non-periodic sounds, which are either played on purpose or avoided depending on the cultural and musical context. We investigate non-periodic sounds produced by two types of flute-like instruments, namely, an alto recorder and traditional pan-like flutes from Central Chile. We adopt a nonlinear dynamics point of view to characterize the multiphonics produced by the alto recorder and the sonidos rajados produced by the Chilean flutes. Our results unveil the common quasiperiodic nature of the two types of sound regimes and suggest that they result from a similar physical sound production mechanism. This paves the way for a better control of non-periodic sound regimes by the instrument makers.

Music in a bag? Controlling the bag of Majorcan and Galician bagpipes.

After defining the mechanical framework of the bag control of bagpipe, this paper presents a study of the bag pressure control in a musical context through the comparison of six players and two bagpipes: one Galician (gaita) and one Majorcan (xeremies), the latter mainly differentiated organologically by a much larger bag size. General observations first lead to the identification and interpretation of the range of control parameters observed. A more detailed analysis of the control parameters during the production of steady notes highlights the coordination between insufflations and the arm displacement necessary to produce a stable and continuous sound. Finally, the bag pressure variation is observed in a musical context and correlated with the musical task, thus, associating different control strategies to the different bagpipes played by the musicians.

Specific features of a stopped pipe blown by a turbulent jet: Aeroacoustics of the panpipes.

Flute-like instruments with a stopped pipe were widely used in ancient cultures and continue to be used in many musical expressions throughout the globe. They offer great flexibility in the input control parameters, allowing for large excursions in the flux and in the geometrical configuration for the lips of the instrumentalist. For instance, the transverse offset of the jet axis relative to the labium can be shifted beyond the operational limits found in open-open pipes, and the total jet flux can be increased up to values that produce highly turbulent jets while remaining on the first oscillating regime. Some of the fundamental aspects of the acoustics and hydrodynamics of this kind of instrument are studied, like the instability of the jet wave and the static aerodynamic balance in the resonator. A replica of an Andean siku has been created to observe, through the Schlieren flow visualization, the behavior of both excitation and resonator of the instrument.