Crown Princess Masako on Tuesday night joined Crown Prince Naruhito at the last minute for a classical music concert in Tokyo marking the opening of an annual art festival hosted by the Cultural Affairs Agency.

The Crown Prince had been scheduled to attend the event alone at the New National Theater in Shibuya Ward. The Crown Princess has been treated for a stress-induced illness for years.

The couple listened to the performance of "Belshazzar's Feast" conducted by Tadaaki Otaka, the theater's internationally renowned artistic director.