Ravinia Music Director James Conlon gives us a fascinating glimpse of the young Kurt Weill with a production of his very first piece for the musical stage, “Magic Night.” Described alternately as a “ballet with song” and a “pantomime for children,” the work brims with distinctive Weill touches even at the early age of 22, boasting a series of popular dance forms—the waltz, fox trot and can-can, among others—that came effortlessly to the composer who had worked part-time as a pianist in a beer-cellar cabaret. This night will be not only magical, but also musically delightful.