Complex sentence: His relationship with his ex-bandmates, namely Kirke and Ralphs, has remained acrimonious, while the singer still sold out on most of his shows, which featured all the hit songs of Bad Company.
Split into simpler sentences: His relationship with his ex-bandmates, namely Kirke and Ralphs, has remained acrimonious. Brian is still selling out most of his shows which feature all the hit songs of Bad Company.