Complex sentence: In 1997, Question Mark and the Mysterians reformed again, collaborating with New York promoter Jon Weiss, who made the band headliners at his CaveStomp garage rock festivals.
Split into simpler sentences: In 1997, Question Mark and the Mysterians reformed again. They collaborated with New York promoter Jon Weiss, who made the band headliners at his CaveStomp garage rock festivals.