SCHUBERT: "WANDERER" FANTASY. SCHUMANN: FANTASY IN C. Sergei Edelmann, piano. RCA Red Seal 7746-2-RC (compact disc). Edelmann is the authentic article--a real, take-no-prisoners virtuoso of the keyboard, unfazed by technical hurdles that entrap mere mortals. Yet these two quintessentially Romantic essays demand more of a personal response than the Soviet emigre is prepared to give. While observing Schubert's dynamic markings, he fails to bestow much poetry or lyricism upon a work ground in one of the composer's greatest songs. The Schumann fares better in a monumental sort of way; the net effect is exciting, and formally coherent. RCA's sonics (from analogue masters) incline to the clangorous.