Abstract: The invention relates to a key lever for musical instruments, including a swivelling support (1) and a key (3) which closes a finger hole of the musical instrument. The key (3) is provided with a seal (7) for sealing the finger hole and is fixed to the support (1) in such a way that it can be adjusted. A screw (5) extends through a drill hole (4) in the support (1), the drill hole (4) being in alignment with the center of the key (3). The screw (5) is connected effectively to the key (3) and in different positions produces different positions of the key (3) in relation to the support (1). The operating end of the screw (5) is accessible from the side of the support (1) opposite the key (3). According to the invention, a vibration-reducing transition piece (6a) is positioned between the screw (5) and the key (3) and the support (1) has a spherical segment shaped, curved section.