Mister Rogers' Neighborhood (1968)

S1E30 Turning the Neighborhood of Make-Believe upside down

In episode 0030, Mister Rogers makes a charming entrance with a violin and a viola, both safely tucked in their cases. He showcases the instruments before inviting Michael Grebanier to share his talent with the cello. Meanwhile, in the Neighborhood of Make-Believe, Lady Elaine introduces an exciting new boomerang trick that causes quite the commotion, flipping everything upside down.