Since his  naming as the Southbank Centre’s artist-in-residence last fall, Pierre-Laurent Aimard continues his residency this January in London. He performs at the Royal Festival Hall on January 21, reuniting with the Philharmonia Orchestra in a program of the great French impressionists, Debussy and Ravel.  Aimard performs Ravel’s jazz-steeped Piano Concerto in G Major, in an evening that also hears the composer’s Ma mère l’oye Suite, …