A disk drive is disclosed comprising a spindle motor comprising a plurality of
windings for rotating a disk. The spindle motor is rotated by commutating the windings
over a plurality of commutation states, wherein audible noise generated by the
disk drive is reduced by phase modulating the commutation interval. Further audible
noise reduction is achieved by modulating a current applied to the windings which
substantially reduces discontinuities in the torque output of the spindle motor
caused by phase modulation of the commutation intervals.