This article provides detailed information about the reforms in our country, attention paid to art of music, particular, development singing, singer’s voice, sounds, sound waves, and types sound.

[1] Long‐period harmonic Rayleigh waves were observed on seismometers during the 1991 Mt. Pinatubo eruption in the Philippines. The amplitude spectrum of the Rayleigh waves shows two distinct peaks at periods of about 230 and 270 s. In the Earth’s atmosphere, long‐wavelength standing acoustic waves are bounded in a low‐sound‐velocity channel between the thermosphere and the ground. The Rayleigh...

A new possible source of solar 5-minute oscillation is supposed. Weak periodic differential rotation (see Zaqarashvili 1997, hereafter paper I) generates exponentially growing slow magnetosonic waves with period of 22 yr in the radiative interior. The waves propagating with ±450 angles to the radial direction have maximal growth rates. The ideal MHD equations for slow and fast waves are linearl...

We describe two experiments demonstrating that a cylindrical cloak formerly introduced for linear surface liquid waves works equally well for sound and electromagnetic waves. This structured cloak behaves like an acoustic cloak with an effective anisotropic density and an electromagnetic cloak with an effective anisotropic permittivity, respectively. Measured forward scattering for pressure and...

A new class of solitary waves arises in the solution of nonlinear wave equations with constant impedance and no dispersive terms. These solitary waves depend on a balance between nonlinearity and a dispersion-like effect due to spatial variation in the sound speed of the medium. A high-order homogenized model confirms this effective dispersive behavior, and its solutions agree well with those o...