Complex sentence: First appearing as their opening act on their 2004 spring tour, Devine made a small splash among their fan base; however, opening for them again in April 2006 and joining their 2007 Spring tour with Manchester Orchestra greatly increased his fan base and affected his career.
Split into simpler sentences: First appearing as their opening act on their 2004 spring tour, Devine made a small splash among their fan base. However, opening for them again in April 2006 and joining their 2007 Spring tour with Manchester Orchestra greatly increased his fan base and affected his career.