CLASSICAL Schubert, Franz: Symphony No. 9. The Vienna Philharmonic, Sir Georg Solti. London DIGITAL LDR 71057 - If a sumptuously recorded, straight Schubert Ninth is what you seek, look no further. Sir Georg keeps textures rather light and ''Schubertian,'' eschewing the more massive statements of most of his competition. The sound is quite remarkable in its naturalness. If there are no startling innovations or revelations, one can be more than merely grateful for such excellence in straightforwardness.