MAHLER: SYMPHONY NO. 3; "KINDERTOTENLIEDER." Agnes Baltsa, mezzo-soprano; Vienna Boys Choir; Women of the Vienna State Opera Chorus; Vienna Philharmonic conducted by Lorin Maazel. CBS Masterworks M2K-42403 (two compact discs). The Vienna Philharmonic plays like a hundred angels; Maazel is an efficient guide through this longest Mahler symphony; the CBS recording provides the right kind of spatial depth--but somehow the results emerge much too antiseptic for this most flavorful and pantheistic of works. Maazel is so scrupulous at eliciting superior execution that he fails to make much of crucial tempo juxtapositions, especially in the 35-minute opening movement, while mitigating the ardent, pulsing song of the finale. Baltsa's "Kindertotenlieder" (which appears only in the CD format), suffers from the Greek artist's flinty, sometimes fluttery mezzo, scarcely the ideal instrument for communicating the quiet tragedy and consoling poetry of these five songs.