Complex sentence: Callaghan played in many collectives and groups as a teenager growing up in Sligo, and with his brother Dominic formed his first real band, called "Petronella", in around 1998.
Split into simpler sentences: Callaghan played in many collectives and groups as a teenager growing up in Sligo. With his brother Dominic formed his first real band, called "Petronella" around 1998.