CPA Handbook ASPE.3400.18 states "the completed contract method would only be appropriate when performance consists of the execution of a single act or when the enterprise cannot reasonably estimate the extent of progress towards completion".

Can a single act include one repeated action? For instance, a singer has a 1 year contract where she performs once a week. Would the completed contract method be appropriate because all she does is sing. OR would the percentage of completion method be more appropriate, and we would make an entry after every performance?