(Video Link)
I'm not really sure what is going on in this video, but it appears that two musicians on a turntable and a drum set are using speaking, holographic human heads as instruments. That's all of the information that I can immediately find. Warning: some NSFW language.
via NerdCore
Not hearing the crowd doesn't mean much, this sounds like the sound was recorded directly from the console, not from microphones in the room.
Beyond the Haunted Mansion Ball room, another famous use of Peppers ghost is when The Gorillaz play a live awards show.
The most difficult bit (other than the room on stage needed to do Peppers Ghost with a huge piece of glass) is that the footage on a turntable would have to have been shot similarly, with the samples being spoken on a turntable. And probably multiple monitors, one per holographic head.
http://www.youtube.com/watch?v=LuK3npk75vE&channel=beardyman