Matinee musicale. On a sunny day off Sloane Square, it was a perfect idea to skip lunch and listen instead to an hour of French songs. The singer was Susan Graham, the acclaimed Texas-born mezzo who has made a speciality of this repertoire, like Frederica von Stade before her. Ever since the Twenties, when young expatriates travelled to Paris to study with Nadia Boulanger, there’s been a preference in New York and Boston, now rather slim, for chansons over lieder. Graham has made a recording of songs by Ned Rorem, who duplicates the ephemeral delicacy and finely etched sophistication found in Ravel, Poulenc, and Debussy. The virtues of the French art song are either delectable or debatable, depending on your orientation. Paris or Vienna? I lean so far to the latter that I hesitated about going to hear Graham’s recital, but I knew her singing would be very accomplished, so I took my seat in the front row at Cadogan Hall.