It’s been nearly 10 years since the Hanson brothers broke out with the perfect pop single “MMMBop.” After two major label releases, they returned as a more mature-sounding, indie-label band in 2004, touring the world behind the album Underneath. As they prepare to release their 4th album in 2007, they’ve recorded their most grown-up song yet, “Great Divide.”

The gospel-flavored rocker features a South African children’s choir singing “I Have Hope” in their native tongue and serves as a rally cry to combat the AIDS epidemic crippling Africa. The track will appear on their upcoming album, The Walk, but is now available for download on iTunes. All revenue generated from sales of the single will be donated to the Perinatal HIV Unit at Chris Hani Baragwanath Hospital in Soweto, South Africa.

The band also shot a video for “Great Divide,” which shows them and the children recording the song. You can watch it, download the song and learn more about the cause with this eCard. You can also just go to iTunes right now, buy the song and show your support. Not only is it a no-brainer to contribute 99 cents to this fund, you actually get a pretty darn inspired Hanson song out of the deal.