Four CD set. Few great conductors can be classified by just a few characteristics. Although this cautionary remark applies to Dimitri Mitropoulos, it seems safe to say that, among other things, he was renowned for performances of intensity and animation; his willingness, even eagerness, to explore unfamiliar repertory; and his photographic memory. Ample evidence of the first two characteristics can be heard in this collection of live performances, many previously unreleased, with the Philharmonic-Symphony and the NBC Symphony Orchestra in repertoire with which his career was closely associated. The two volumes include works by Busoni, to whose circle he had belonged as a student in Berlin, the Twelve-tone Viennese masters for whom he fought major cultural battles, Prokofiev, Richard Strauss, and Mahler, whose inner landscape he found congenial and helped popularize in his decades in America. Digital restorations in 2008 utilizing the revolutionary harmonic balancing technique.