"Our World," the first live global satellite broadcast, took place on June 25, 1967. While it featured people and performers from around the world - hence the title - a very notable piece of this revolutionary broadcast featured The Beatles singing "All You Need Is Love" for the first time publicly - VERY publicly. An orchestra played with the Fab Four in the real-time broadcast, and in attendance singing along were the likes of Rolling Stones Mick Jagger and Keith Richards, Marianne Faithfull, Paul McCartney's fiancee at the time Jane Asher, George Harrison's wife Patti Boyd, producer George Martin (who stressed about it the most, being responsible for its smooth execution on a global stage), and a whole bunch of others. Billions of people watched the live broadcast from all over the world.
But before you do it for real, it's a good idea to rehearse. And The Beatles did just that, not too long before the real global satellite broadcast. Here's the rarely-seen rehearsal footage, before the single take they needed to introduce the song to the world in real time.