The Detroit Symphony has been searching for a new music director for a couple of years now, with no visible frontrunner emerging. But could Andrew Davis, who will shortly leave a leadership post with the Pittsburgh Symphony, be the DSO’s knight in shining armor? “Not that the DSO should act rashly. But 16 minutes into this concert, after a perfectly exquisite, poised, witty, not to say airborne turn through Haydn’s little Symphony No. 22 in E-flat, I would have been pushing a contract into Davis’ hands and filling his ear with honeyed promises.”