What could be more romantic than being awakened by a birthday serenade played by 13 musicians on Christmas morning? That was Wagner’s gift to his beloved wife, Cosima. Gorgeous melodic lines, especially for the demanding “perpetual motion” ending, are called for in Barber’s Violin Concerto. Our concert concludes with Sibelius’s late-Romantic symphony. In the finale, listen for the “incomparable swan hymn,” inspired by a breathtaking flight of 16 swans, as well as and washes of sound that lead to six crashing chords, separated by eloquent silences.