BONANZA

That was an episode called "Enter Thomas Bowers" from 1964, near the beginning of the Civil Rights Movement.
The story concerned a black opera singer who had been engaged for a concert performance by a ladies' cultural organization which was unaware of his race.
The gist of the episode was about the prejudice and discrimination this man suffered in Virginia City, and how the open-minded Cartwrights came to his aid, especially since it was believed that he was a fugitive slave.
While I don't remember certain details, it did end with Mr. Bowers performing beautifully at the civic center.

Over the years. BONANZA has tackled the subject of bigotry against Jews, Asians, and especially Indians.
Quite unusual for any TV show of that period, but especially for a Western!