George Harrison's Bangladesh show keeps giving

George Harrison's concert for Bangladesh will celebrate its 40th anniversary on Monday. The concert wasn't just a historic event for the drought and famine-ravaged region - it was also a historic event for musicians everywhere.

When Harrison took the stage at New York's Madison Square Garden on August 1, 1971, he hadn't performed publicly since the Beatles' last concert in 1966. But, as they say, he got by with a little help from his friends. The famous concert and its recordings raised millions for the broken country; it also changed the face of celebrity activism.

The problem was a humanitarian crisis in Bangladesh, "Early Show" co-anchor Jeff Glor reported. The friend who asked Harrison for help was Indian musician Ravi Shankar.

Andrew DeCurtis, of Rolling Stone magazine said of the concert, "Back in 1971, the idea of seeing any of the Beatles on the stage was a pretty electrifying concept. They had not performed as a band since 1966."

Jon Taplin, producer of The Concert for Bangladesh, told CBS News, "(Harrison) called me and said, 'I want to do this live show, and I want to get as many of our friends together as we can,' and so I said, 'OK, I'm in, I want to do it."

Legends like Bob Dylan, Eric Clapton, Leon Russell and Ringo Star showed up to help Harrison with the concert.

"(The stars who signed on) generated a huge amount of excitement and a huge amount of attention, which of course, it was meant to do," DeCurtis said.

Caryl M. Stern, chief executive officer of UNICEF, told CBS News, "I don't think anyone in the world has ever done anything on that scale before, but he brought together musicians and he used music for good."

That day - almost 40 years ago - Harrison and his friends helped put Bangladesh on the map. What's more - they gave musicians a new way to give back.

"The template was set by Bangladesh," DeCurtis said. "It becomes sort of the emotional backdrop I think for, you know, Live Aid and all the other concerts that have come over these few decades."

In 1985, nearly two billion people across 150 nations watched Live Aid, a televised, dual-city concert held in London and Philadelphia

Later that year came Farm Aid, the brainchild of Willie Nelson.

The show was such a success that Nelson has hosted one almost every year since, raising millions and continuing what's now a trend: whenever there's a national or international crisis, musicians unite.

Stern, of UNICEF said, "They understand that there are people who live in places that many of us can't find on a map, whose voices won't get heard, who don't have a microphone to sing through."

U2 frontman Bono took aim at the G-8 in 2005. He helped organize Live 8, a set of eight concerts in eight cities, involving more than 1,000 musicians.

Inspired by Live 8, Al Gore decided to go even bigger. On July 7, 2007, Live Earth aired, a 22-hour, globally-broadcast series of concerts held one-by-one, on each continent.

Madonna said during her concert in the Live Earth, "These concerts all around the world aren't just about entertainment, they're about starting a revolution."

DeCurtis said, "I don't think George Harrison thought of this as a revolutionary idea. Let's have these massive concerts. 'What can I do? I'm a musician, I've got these friends. Let me just call them up. We'll play a show.'"

Taplin added, "That was a good thing, a benefit, literally a benefit concert."

The concert began as a favor for a friend and ended up redefining the way the world responds to a crisis.

Glor added on "The Early Show" the concert itself generated $250,000 for Bangladesh, but sales of the album afterward generated $15 million for UNICEF.

Apple Records and UNICEF have joined forces to celebrate the concert's 40th anniversary. Starting today, the 1971 Concert for Bangladesh is available for free streaming on iTunes through Monday. The hope is that people will see the concert and then download the album. All proceeds go towards the George Harrison Fund for UNICEF, which is now being used to help children in the troubled Horn of Africa region.