When Rabbi Mordechai Becher taught in Yeshivas Ohr Somayach, he took a talmid who was a professional classical musician to visit his rebbi, Rav Moshe ztz”l. Rav Moshe described the talmid’s musical career as an umnus nekiyah v’kalah, a Talmudic phrase roughly meaning “an honest and refined profession.” When the talmid asked if he could play Bach’s music, Rav Moshe replied that it was permitted because music cannot be mekabel tumah, cannot receive spiritual impurity.