Complex sentence: Though nearly everyone in the group was from an Los Angeles, California based band called Stonehenge, the group's line-up was revamped with the introduction of Michael Fennelly, who had been one of the principal vocalists and songwriters in The Millennium.
Split into simpler sentences: Though nearly everyone in the group was from an Los Angeles, California based band called Stonehenge, the group's line-up was revamped with the introduction of Michael Fennelly. Fennelly had been one of the principal vocalists and songwriters in The Millennium.