Oh my goodness. This was me giving a presentation in Luxembourg yesterday, whilst simultaneously tuning a piano in Kigali.
No, not a hologram, a pre-recorded tape, played at the first rehearsal day ahead of the TEDx talk on 26th October. You wouldn't believe how difficult it was to record that with a very grainy webcam and upload it over a limited 3G connection. Took a few attempts, but got there in the end.
I'll definitely be there for the second rehearsal on 24th October, though. Looking forward to meeting all the other speakers. I have videos of their rehearsals too, which I'd love to watch, only... 3G, limited.
Never mind. You can find out all about them on the event website.