From the YouTube page: Judy Garland only performed “Over The Rainbow” twice during her many television appearances, which spanned 14 years. She performed it on her first TV Special, “Ford Star Jubilee” in the episode called “The Judy Garland Special” in 1955, and sang it to her children on The Christmas Edition of her weekly TV show “The Judy Garland Show” (1963).
Here Judy is dressed up as the tramp character she played when doing a duet with Fred Astaire in the film ‘Easter Parade’.
Beside the fact that it’s a terrific performance, I’d note that at this time in the 1950s artists didn’t perform so openly and with such raw emotion. It wasn’t really done much at the time, which makes this performance even more impactful. Judy was simply being who and what she was, which was authentic and original.