America the Beautiful
Judy Garland

Judy had originally conceived an Americana tribute to the recently assassinated JFK. The network balked thinking that it was too political at the time. She was able to sneak in Battle Hymn of the Republic at the end of the show following his death, then performed an entire program of patriotic material later in the season. Her performance of these two anthems are perhaps among the greatest moments in television.

From the YouTube comments:

How many big stars would come out today on stage with smudged makeup, wearing dingy clothes, having just done a vaudeville’style comedy routine. The stars of yesteryear weren’t afraid to get dirty…and to actually work at entertaining. Today, it’s all red carpets and personal assistants and contract clauses for evian water and fresh fruit.