Shameless Google bait time.
CM Punk's new entrance theme song that he debuted tonight is "Cult of Personality," the leadoff single from Living Colour's seminal debut album "Vivid." He had previously used the song as his entrance music in Ring of Honor during his farewell "Summer of Punk" heel run in 2005. After winning the ROH World Championship in his "last match before leaving for WWE," he turned heel and promised to take the belt to WWE. He even "signed his WWE contract" on the belt. He lost the belt to James Gibson/Jamie Noble on his actual penultimate night in ROH. Noble had re-signed with WWE, so he did the opposite gimmick, that he was staying in ROH until he lost the title. Gibson lost the title to Bryan Danielson/Daniel Bryan after a month.
You can buy an MP3 of the original recording of "Cult of Personality" from Amazon. The (excellent) full "Vivid" MP3 album can be purchased here. The CD can be purchased here.
Living Colour re-recorded the song last year, presumably to have control over the recording for licensing and make more money from selling it. That version is available here. This is far from unprecedented, as Squeeze did this for all of their hits last year and released it as "Spot The Difference." (MP3 here, CD here).