The PBS show about Andrew Carnegie must have been filmed at "Clayton",
the mansion of Henry Clay Frick in Pittsburgh.  Frick was a major mover
and shaker in the early steel and coke industries.  The house contains
its original Welte orchestrion, restored by Durward Center when the
property was opened to the public in 1990.  Read about this beautifully
preserved piece of history at  http://www.frickart.org/features/clayton/

Richard Vance