Musicians and nonmusicians synchronized drum-beating movements to sound sequences composed of 90 successive interonset intervals that increased or decreased continually by various amounts of time. After the end of a sequence, they continued to produce 30 beats without interruption. Synchronization appeared both smooth and accurate for all levels of changing tempo. In general, actions preceded sounds with increasing intervals and lagged behind sounds with decreasing intervals, indicating that the stimulus change was not fully predicted. There was a tendency for the continuation intervals to change in the reverse direction of the preceding synchronization intervals, suggesting that the system retains information about the tempo change. We discuss these results in terms of the demands tempo change makes on timing mechanisms, and what they reveal about participants� ability to create and sustain an internal nonisochronous periodic process.