My friend and me,  looking through her red box of memories  ...    The Verve - Sonnet (subtitulado)  from MHtv1  on Vimeo .
Sound is a travelling wave which is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations