Sean Parker’s Spotify went into battle with Myspace, co-owned by Justin Timberlake (who played Parker in “The Social Network”), over the hot band Mumford & Sons at the South by Southwest festival in Austin. Management for the Grammy-nominated British folk rockers negotiated with both Myspace and Spotify about playing at their respective parties during the festival. Sources tell us Facebook co-founder Parker was keen for Mumford to perform at Spotify’s Thursday night bash in Austin alongside A$AP Rocky. But a source told us, “Sean really wanted Mumford & Sons . . . but in the end Mumford played the Myspace show Saturday night at the University of Texas to 8,000 fans.” Despite that (and rumors that Parker may still be sore over Timberlake’s portrayal of him in the Facebook flick), Parker still was not going to miss the band. Our source said, “Imagine everyone’s surprise when Parker then showed up at the Myspace concert to check out the competition.” Bryan Ling, who manages LA group Edward Sharpe & the Magnetic Zeros, who appear with Mumford & Sons in the film “Big Easy Express,” told us he had negotiated with both Spotify and Myspace, but decided to go with the latter because it was the better platform to promote the movie, which world-premiered at SXSW. Ling said, “This wasn’t about money, this was about the film. We wanted to do something special to promote the film. I came to Sean and Spotify with the idea, but we realized Myspace had the better platform to show the trailer, and through that fans would sign up for the show. The bands didn’t get paid.” Despite that, Parker was in fine fettle at SXSW, boldly declaring that Spotify “will overtake iTunes in terms of the amount of revenue we contribute to the music labels in under two years.” Myspace declined to comment.