Among the many musicians who fought on behalf of the West Memphis Three -- a trio of Arkansas men convicted as teenagers in 1993 for a series of child murders they did not commit -- was Eddie Vedder. The Pearl Jam frontman was instrumental in raising money and awareness, and thanks in part to his efforts, Damien Echols, Jessie Misskelley Jr. and Jason Baldwin were freed in August 2011 after spending more than 18 years in prison.

In an exclusive video (below), Vedder talks about writing the ukulele ballad 'Satellite,' his contribution to the soundtrack for 'West of Memphis,' a new documentary about the case.

Vedder penned the tune -- first heard on his 2011 album 'Ukulele Songs' -- for Lorri Davis, a woman who began corresponding with Echols after seeing the 1996 HBO documentary 'Paradise Lost: The Child Murders at Robin Hood Hills.' The two married in 1999, while Echols was still on death row, and Davis spent the next decade working to clear her husband's name. It was an uphill battle, as local authorities had used the trio's interest in heavy metal to concoct a story involving Satanism and ritual killings, but she didn't have to go it alone.

Perhaps because of the metal angle, the case caught the attention of numerous big-name musicians, many of whom appear on the 'West of Memphis' soundtrack. Due out Jan. 15, the album features everyone from punk legend Henry Rollins to country superstar Natalie Maines. Nick Cave and Warren Ellis composed the film's original score, while Johnny Depp -- a longtime West Memphis Three supporter who's become close friends with Echols -- plays guitar on three tracks, including Marilyn Manson's cover of Carly Simon's 'You're So Vain.'

As Vedder explains, he recorded 'Satellite' years ago, back in the "pre-cell phone" era, and that allowed for the happy accident captured in the track's closing seconds. Watch the video to get the full story -- then click here for more information on the film.

Watch Eddie Vedder Discuss 'Satellite'

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