Creating a stage musical is a long and complex undertaking.  An author doesn’t know how the show will actually play until it is in front of a real audience.  A “29-Hour Reading” is a reading of a play or musical, typically for developmental purposes, where the Actors’ Equity Association (AEA) allows Equity members to participate for a maximum of 29 hours of rehearsal and performance within a 14-day period, without a full Equity contract.  This is often a very important first step in getting a musical on the road to Broadway.