Minor change to MusicModel for in-memory orc and sco during performance.
Minor change to MusicModel for in-memory orc and sco during performance.

csound/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,csound/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,csound/csound,csound/csound,csound/csound,csound/csound,csound/csound,ketchupok/csound,csound/csound,csound/csound,csound/csound,ketchupok/csound