Designation used in piano music indicating that a specific passage is to be played by the right hand. M.d. are the inititals for the French words main droite ( main means hand and droite means right). M.d. are also the initials for the Italian words mano destra ( mano means hand and destra means right).See also [Eng.] R.H. ; [Eng.] right hand; [Fr.] main droite; [It.] M.d. ; [It.] mano destra; [It.] C.d. ; [It.] colla destra; [It.] col destra.Also[Eng.] L.H. ; [Eng.] left hand; [Fr.] M.g. ; [Fr.] main gauche; [It.] M.s. ; [It.] mano sinistra; [It.] C.s. ; [It.] colla sinistra; [It.] col sinistra.<br><br>Musical Instrument Digital Interface, a digital signal system, or a system of number signals, used to communicate performance information to and from musical instruments making music.