Schumann’s lilting “Des Abends” introduces Dénes Várjon’s ode to the night, with music from Germany, France, and Hungary. Schumann’s Phantasiestücke refer to more than the literal darkness though. Barred from seeing his beloved fiancée, the German expresses his torment in beautiful, poetic music. Ravel’s haunting Gaspard de la nuit, one of the most difficult piano works ever written, describes nightmarish images of strange creatures, tolling bells, and murky, watery depths. And at the heart of Bartók’s Im Freien lies “Klänge der Nacht,” starring the mesmerizing sounds of cicadas, birds, and frogs. Várjon is a compelling nighttime guide.