Complex sentence: Smooth jazz returned at Noon on August 22,1997 as WSJZ, after a format swap with what had been WOAZ (now WCRB); in September 1999, it flipped to Talk, completing a 4-month transition to the format.
Split into simpler sentences: Smooth jazz returned at Noon on August 22,1997 as WSJZ, after a format swap with what had been WOAZ (now WCRB). In September 1999, it flipped to Talk, completing a 4-month transition to the format.