Grunge rockers Soundgarden released a new single Tuesday morning, which will be available as a free download for one week on iTunes.  Titled "Live to Rise," the track is the first release of new Soundgarden material in 15 years, and will be included on the soundtrack for the upcoming Disney film, "Marvel's The Avengers."  The film is scheduled to arrive in theaters May 4th, and the soundtrack, which also features tracks from Shinedown, Bush and Five Finger Death Punch, will arrive in stores May 1st.