By Sebastian Usher
BBC world media correspondent
The organisers of Live 8 say 85% of the world's population would have been able to tune in to the event to hear its message on global poverty.
Crowds gather at a screen in Moscow's Red Square
Dubbed the biggest global live event in history, the concerts are available throughout the world on TV, radio and the internet.
The size of the audience is key given the aim to raise public pressure on the world's leaders to act.
Only the Olympics and football World Cup can compare in global reach.
TV stations across Europe are broadcasting the concerts live.
Across the world, more than 140 TV channels are showing the event and some 400 radio stations.
Many are using feeds from the BBC's coverage, while the US-based music channel, MTV, is also supplying coverage to a variety of TV stations.
It has been a complicated technical feat to provide global broadcast coverage so quickly.
The advances in digital technology over the past few years mean that Live 8 is interactive in a way that could only be imagined when Live Aid was staged 20 ago.
The worldwide event kicked off with the Tokyo show
Viewers with digital TVs or broadband internet access can pick and choose which concerts they watch.
America Online (AOL) is providing a free stream of all the concerts on the internet, although you need a broadband connection to see it properly.
AOL even made a deal with China so the event could be seen there on the internet with a delayed stream.
The Live 8 organisers are hoping these new and older technologies will help muster a worldwide audience of two billion people - 500 million more than those estimated to have tuned in to Live Aid.
But in some parts of the world - most notably Africa itself - this profusion of new technologies means little, as few people have access to them.
This is one of the inequalities that Live 8 is, of course, hoping to help redress.