Who is Mitch Lewis in the novel, The Girls?

Mitch Lewis is a famous musician who has become disenchanted with his wealth and fame and seeks out a different kind of life. As a result, he comes into contact with Russell and the girls but, unbeknownst to him, they are only really interested in him for his money and access to the trappings of fame. When Mitch fails to follow through with the record deal that Russell believes he was promised, Mitch is targeted by Russell and the girls and the brutal murders are carried out at his home, although Mitch is coincidentally not present that night.