John Valby

From OAPedia.com

John Valby, nicknamed "Dr. Dirty", is a comedian/musician featured in a classic O&A show segment which was one of the funniest segments in the early days of the XM pogram. Because he didn't bring his own keyboard with him that day, he played two filthy songs on a large, expensive piano in the beautiful, high-class Steinway piano showroom downstairs from the XM studios, much to the horror of the Steinway staff members who were present.