Abstract: Described here are bioelectric modulation systems and methods for generating rotating or spatially-selective electromagnetic fields. A modulation system includes a multichannel electrode with independently controllable electrode channels that can be operated to generate rotating electromagnetic fields that stimulate cells regardless of their orientation, or to generate spatially-selective electromagnetic fields that preferentially stimulate cells oriented along a particular direction. The bioelectric modulation system may be implemented for stimulation of neurons or other electrically active cells. The bioelectric modulation described here may be used for a variety applications including deep brain stimulation (DBS), spinal cord and vagus nerve stimulation, stimulation of myocardial (heart) tissue, and directional stimulation of muscles.