The illustrious pianist Emanuel Ax arrives in Rochester on Monday with an excellent program of intimate impromptus, both classic and new. Ax will present Franz Schubert's alluring and enigmatic Four Impromptus alongside rising contemporary composer Samuel Adams' "Impromptu 2 'After Schubert.'" The program also features music by arguably the most beloved composer for the piano, Frédéric Chopin, including his elegant Sonata No. 3 in B Minor. Ax is a performer who brings both joviality and gravitas to Chopin, often in the same phrase. The Eastman School has long hosted upper-echelon chamber music concerts and this one ranks right at the top.