The woodwind section of the modern orchestra includes flutes, oboes, clarinets and bassoons and related instruments, although flutes are generally no longer made of wood. These instruments are all aerophones, blowing instruments, the sound produced by blowing across an aperture in the case of the flute, by the vibration of a single reed in the case of the clarinet and by the vibration of double reeds in the case of the oboe and the bassoon.