Complex sentence: By then, Raitt was clean and sober, having broken her substance abuse--for which she credited Stevie Ray Vaughan in a Minnesota State Fair concert the night after Vaughan's 1990 death.
Split into simpler sentences: By then, Raitt was clean and sober, having resolved her substance abuse problem. She later credited Stevie Ray Vaughan for his help in a Minnesota State Fair concert the night after Vaughan's 1990 death.