A musical instrument playing actuator, includes an elastic diaphragm which
has a through hole, wherein an annular projection portion is provided on
the elastic diaphragm so as to project toward the diaphragm member, a
diaphragm member which is arranged to oppose to the elastic diaphragm and
is formed movably toward the elastic diaphragm, a wall structure body
which forms an enclosed space together with the elastic diaphragm, the
diaphragm member, and the projection portion when the diaphragm member is
moved toward the elastic diaphragm to contact the projection portion, and
an air inlet which communicates the enclosed space with an outside.