Twenty-five years ago Tuesday (July 13), Bob Geldof and Midge Ure moved mountains, arranged satellites and assuaged rock-star egos to pull off one of the most monumental concerts in history. [article id="1643506"]Live Aid, the transatlantic charity bash[/article], brought together the biggest names in music -- all of whom played for free -- on two massive stages in London and Philadelphia, beamed their performances out to the entire world (including here in the U.S. on a fledgling cable network called MTV) and managed to raise hundreds of millions of dollars for famine relief in Ethiopia.

It was, shall we say, a pretty incredible event -- one Geldof rather shockingly booked in roughly three weeks, mostly on a whim (he was knighted for his efforts). And it's not exactly hyperbole to say that it changed the world and defined an entire generation. So in celebration of Live Aid's 25th anniversary, we decided to break out the calculators and crunch the numbers a bit. Here are some of the figures that helped make history.

1.5 billion: The estimated number of viewers who tuned in to watch the concerts, in 100 different countries.

150 million pounds: The amount that Live Aid raised for famine relief in Ethiopia. It works out to some $245 million U.S.

162,000: The number of people who attended the two main Live Aid concerts -- 72,000 in London's Wembley Stadium and 90,000 in Philadelphia's JFK Stadium. There were, of course, other concerts held in conjunction with Live Aid, in Sydney (OZ for Africa) and Cologne, Germany, to name a few. Bands also taped performances from Moscow, Japan, Austria, Norway and Yugoslavia.

70: As best as we can count (using detailed Live Aid sites like this one), this was the total number of acts/artists that performed on the stages in London and Philadelphia. It's a list that includes Madonna, U2, Mick Jagger, David Bowie, Elton John, Queen, Black Sabbath, Run-DMC, Santana, Tom Petty & the Heartbreakers, Neil Young, the remaining three members of Led Zeppelin, Duran Duran, Bob Dylan and Tina Turner. Of course, we're not counting the prince and princess of Wales (who appeared at Wembley), any of the celebs who introduced all the acts, everyone who joined in for the group finales at either concert or the artists who appeared in taped performances from around the globe. If you really want to get technical, here's a list of everyone -- musician, actor, comedian, royalty -- who participated.

16 hours: The continuous length of the entire Live Aid concert. The show in London started at noon and ended at 11 p.m. In Philadelphia, things got under way at 8:51 a.m. and ended at 11:05 p.m. (4:05 a.m. in London), meaning that the entire thing ran for 16 hours. Though, as you can see, between London and Philly, there were actually more than 27 hours of total performances.

1: The total number of artists who appeared at both the London and Philadelphia concerts. It was Phil Collins, who, after performing at Wembley, took a helicopter to Heathrow Airport, hopped on the Concorde and made it to JFK Stadium to do a second set -- and play drums for Eric Clapton and the reunion of the former members of Led Zeppelin. He also reportedly convinced Cher -- whom he met on the Concorde -- to take the stage in Philly. What can we say? The man was dedicated.

What are your memories of Live Aid? Let us know in the comments!