Mark Cappelli is something of a rarity in the world of piano technicians: He has a master’s degree in piano performance and has been tickling the ivories since he was a toddler. Pickle Piano Company, a retailer in Bloomingdale, praises Cappelli for his pitch-perfect ear, a talent that the Grant Park Music Festival, Chicago Symphony Orchestra, and Ravinia have all benefited from. (Can’t get on his schedule? Call his capable younger brother, Jeff, who runs Westmont’s Chicago Piano Service.) Cost to tune a typical piano: $110.