The accordion's body consists of two wooden boxes joined together by the bellows. These boxes house reed chambers for the right- and left-hand manuals. Each side has grilles in order to facilitate the transmission of air in and out of the instrument, and to allow the sound to project better. The grille for the right-hand manual is usually larger and is often shaped for decorative purposes. The right-hand manual is normally used for playing the melody and the left-hand manual for playing the accompaniment; however, skilled players can reverse these roles and play melodies with the left hand.