This research was designed to determine whether musicians' learning is affected by the time intervals interposed between practice sessions. Twenty-nine non-pianist musicians learned a 9-note sequence on a piano keyboard in three practice sessions that were separated by 5 min, 6 hr, or 24 hr. Significant improvements in performance accuracy were observed in Session 2 only in the group whose sessions were separated by 24 hr. There were significant increases in performance speed in Session 2 in all three practice conditions, results which likely were attributable to the inclusion of all Session 1 data in the analysis. Additional significant speed increases were observed in Session 3 only in the groups whose sessions were separated by 6 and 24 hr. These results suggest that sleep-based procedural memory consolidation may enhance performance accuracy in music skill learning, whereas enhancements in performance speed may be attributable to both wake- and sleep-based consolidation processes. (Contains 4 notes and 3 figures.)