In Toronto, a new hall meant to house the Canadian Opera Company and the National Ballet has turned up some cultural differences between the two groups and how they’d like to use the building. “A good deal of horse-trading went on as to who would use the 12 less desirable weeks, particular those in the hot summer months. In the end, both companies accepted some of them. But the ballet, being a tenant rather than a partner in the project, had the weaker bargaining position. Its season will now push into July.”