Abstract: An adjustable keyboard for electronic instruments having a pair of demi-boards which are extendable from a retracted, flat position to an extended, tetrahedal position wherein the distal side of one of the demi-boards is located closer to the other demi-board than the proximate side, the first and second demi-board planes intersect with the base plane to form an acute angle, the first and second demi-board planes intersect with each other at an apex intersecting line being in non-parallel alignment with the base plane and the first and second demi-board planes and the base plane intersect at an intersecting point in space on the distal side of the base member. A split spacebar may be actuated by movement about an axis parallel with the longitudinal axis of the demi-boards in either direction from a normal position and also on lateral movement along the said longitudinal axis.