Pop Art competed at the 2010 Alltech FEI World Equestrian Games (Ky.), the 2008 London Olympic Games, the 2009 FEI World Cup Finals (Nev.) and dozens of CDI Grand Prix classes. Spectators know his name, and announcers know his history. For Jill Irving, who’s leasing the 16-year-old gelding from his previous rider, Canada’s Ashley Holzer, going down centerline the first time aboard the famous chestnut was a bit unnerving. But now?