An apparatus for dispensing a volatile substance includes an electromechanical d ispenser (2) attached to a pivot arm (29), and a cartridge (60) for holding a pl urality of reservoirs (31) each containing a volatile substance. The cartridge (60) is rotatable such that any one of the reservoirs (31) can be positioned in an engagement position, in which the volatile substance can be dispensed. The c artridge (60) has a cam feature consisting of a contoured circumferential surfac e that alternately rises and falls. The pivot arm (29) operates in tandem with the cam feature such that, when the cartridge (60) is rotated, the dispenser alt ernately engages and disengages from successive reservoirs (31), and remains out of the path of motion traversed by the reservoirs (31) as the cartridge (60) ro tates from one engagement position to a subsequent engagement position. The ele ctromechanical dispenser (20) may be a piezoelectrically actuated vibratory type liquid atomization apparatus, and the volatile substance may be a fragrance.