Under the seductive title “Le promenoir des deux amants,” the fluffy-bearded bass-baritone William Socolof (who once made his debut in Leonard Bernstein's “Mass”) will give an afternoon concert at Britz Castle with pianist Jacob Greenberg. In addition to songs by Franz Schubert and Arnold Schoenberg, the audience can also look forward to French works by Darius Milhaud and Claude Debussy.