Complex sentence: In 2008, the band reunited for touring purposes, released its first new single in fifteen years in September 2013, and released its first full-length album for 17 years in March 2015.
Split into simpler sentences: In 2008, the band reunited for touring purposes. They released their first new single in fifteen years in September 2013, and their first full-length album in seventeen years in March 2015.