A keyboard-operated tone-producing apparatus having, in combination, keyboard means the keys of which are mounted for downward depression to effect tone production in the apparatus and for longitudinal sliding to alter or bend the tone; electronic digital signal processor means; tone-generating means; pressure sensing means responsive to key depression to produce signals corresponding thereto for application to the signal processor means to produce corresponding digital signals applied to generate tones from the tone-generating means; means for causing the pressure sensing means to provide the same signal reference, upon key depression, irrespective of the point of pressure along the path of longitudinal sliding of the key; and means controlled in response to the last-named means and cooperative with the signal processor means as it controls the tone-generating means to produce one or all of variable range bending of the tone, center compensation for differing player techniques of key depression, and second striking of the key while depressed for second tone generation.