Complex sentence: This event came in the middle of Clarkson's well-documented artistic battles with her record company and management, who wanted her to promote her new single "Never Again"; she thought to do so at a charity event would be "beyond crass".
Split into simpler sentences: This event came in the middle of Clarkson's well-documented artistic battles with her record company and management. They wanted her to promote her new single "Never Again", while she thought to do so at a charity event would be "beyond crass".