An entertainment system comprises at least one input for receiving data representative of a reference dance performance, a dance analyzer for generating data descriptive of an aspect of the reference dance, a key-point selector for selecting a plurality of key-points in the reference dance responsive to a property of the reference motion data, and an error tolerance calculator for generating error tolerance values at the plurality of key-points in the dance for use in scoring subsequent performances of the dance. The error tolerance values are responsive to a property of the reference motion data. An input may receive telemetry from one or more game controllers in communication with the entertainment system, in which the reference motion data comprises motion data generated by the dance analyzer from the telemetry received from one or more game controllers while the controller(s) was held during the reference performance of the dance.