What actors and actresses appeared in Sills Burnett at the Met - 1976?

There seems to be a misunderstanding. "Sills Burnett at the Met - 1976" doesn't refer to a specific production or performance at the Metropolitan Opera.

It's possible you are referring to:

* Beverly Sills - a famous American soprano who performed at the Metropolitan Opera extensively. She retired in 1980.

* The Metropolitan Opera - a renowned opera house in New York City.

To provide you with accurate information about actors and actresses who appeared in a specific opera performance at the Met in 1976, please specify:

* The opera title: What opera was being performed?

* The date: Was it a specific date in 1976, or a range of dates?

Once you provide this information, I can help you find the cast list for that specific performance.