Complex sentence: Soulscar was formed in 1997 as a solo project of Andrew Staehling, who released several demos with the help of hired musicians, among whom was Jeff Waters of Ottawa-based Annihilator.
Split into simpler sentences: Soulscar was formed in 1997 as a solo project of Andrew Staehling, who released several demos with the help of hired musicians. Among those who contributed to these demos was Jeff Waters of Ottawa-based Annihilator.