The Alexandria Symphony Orchestra will feature two spring concerts this year. Bernstein features the Choral Arts Society of Washington and Artistic Director Scott Tucker weaving an evening of masterworks with the Choral Arts Chamber Singers. One of his finest liturgal works, written for “troubled times,” Haydn’s Lord Nelson Mass triumphantly marries the chorus and orchestra. Also on the program: Bernstein’s Chichester Psalms, Brahms’ Nanie and Variations on a Theme by Haydn. In New World Symphony, the National Symphony Orchestra at Wolf Trap conductor Emil de Cou presents Dvorak’s epic Symphony No. 9 (From the New World). Written as both a tribute to his immigrant roots and his adopted homeland, this American-inspired work borrows from Native American song, African-American spirituals, Scottish melodies and Dvorak’s own Czech folk traditions.