Complex sentence: The band was set to open for Cinderella and Warrant during their summer 2008 tour, however, due to Tom Keifer of Cinderella having a hemorrhaged vocal cord, the tour was cancelled.
Split into simpler sentences: The band was set to open for Cinderella and Warrant during their summer 2008 tour. However, due to Tom Keifer of Cinderella having a hemorrhaged vocal cord, the tour was cancelled.