Timing profiles of live and imagined performances were compared with the aim of creating a context-specific measure of musicians' imagery ability. Thirty-two advanced musicians completed imagery use and vividness surveys, and then gave two live and two mental performances of a two-minute musical excerpt, tapping along with the beat of the mental performances. Profiles of inter-beat-intervals for each performance were generated; correlations were calculated within and between the two performance conditions and then compared with results from the surveys. All participants achieved a significant correlation between the timing profiles within the live condition, while less than 70% did so within the mental condition and between the two conditions. Significant correlations emerged between the imagery vividness measures and results from the live condition, and self-reported time spent employing imagery significantly correlated with results from the live and mental conditions. This suggests that mental chronometry can offer an indication of imagery ability, warranting further research to facilitate more accurate interpretations of results and refinement of testing procedures. (Contains 7 tables.)