Billy Greer, the bassist and co-lead vocalist for Kansas, has retired after nearly 40 years in the band. In a message announcing his departure, Kansas thanked Greer for his decades of service. “For 39 years, Billy has been a loyal, dedicated, and immensely talented bandmate. He’s traveled around the world with us including USO tours,” drummer Phil Ehart wrote. Guitarist Richard Williams added that Greer “stood shoulder to shoulder with us through both the ups and the downs. His voice, both singing and emceeing, has been a constant with us on stage. The entire Kansas family will miss him.” Who …