Sir Arnold Weinstock , Managing Director of GEC, has a preference for music written before 1830. He has chosen records of GUNDULA JANOWITZ singing an aria from Bach's St Matthew Passion-' the finest work in all music,' he says-WANDA I.ANDOWSKA playing a sonata by Scarlatti, BEVERLY SILLS singing the Mad Scene from Donizetti's opera =Lucia di Lammermoor, and WILHELM KEMPFF playing a Mozart piano concerto.