At the Metropolitan Opera, it wasn’t until 2017 that Der Rosenkavalier got the kind of radical reboot that is de rigueur in Europe for repertoire across the board. With the rococo froufrou much reduced, this is the version that will be streaming for 23 hours beginning on Sunday, April 19, at 7:30 P.M. E.D.T., one in a daily rotation of free encores from the company’s chockablock live-HD archive. For the last time, Renée Fleming revisits the aristocratic Marschallin, a signature role for her at the Met since 2000. —M.G.