This study investigated functional MRI (fMRI) cerebral correlates of beat- and duration-based sensorimotor synchronization (SMS). We developed an original paradigm to compare SMS in beat-based versus duration-based contexts. In the beat-based conditions, participants synchronized finger taps with a regular beat. The condition had either metrical or nonmetrical subdivisions (2:1 vs. 2.4:1 ratio). In the duration-based conditions, participants synchronized by referring to a cue tone appearing 300 ms ahead of an irregularly occurring target tone. The behavioral results suggest the use of different strategies for beat-based and duration-based conditions. Synchronization accuracy was similar in both types of tasks. However, participants reported higher attentional demands in duration-based conditions. ICA analysis of the fMRI data isolated 2 underlying cerebral networks for all tasks, both more strongly involved in duration-based conditions. The first brain network involved the bilateral superior temporal gyrus, supplementary motor area, and inferior frontal gyrus; the left dorsal premotor cortex and primary motor cortex; and the right posterior cerebellum. The second brain network involved the bilateral basal ganglia, thalamus, inferior parietal lobules, and cerebellum. We suggest that the first network managed temporal information processing and execution of motor commands, and that the second controlled error correction processing. The involvement of the same pool of cerebral resources with different strengths according to the level of regularity of the input may represent a principle of parsimony: as beat-based SMS allows better anticipation, it requires less cerebral resources than duration-based SMS.