OSSCS concludes its 49th season with a wave of fresh air and a ray of sunshine. A season-long retrospective of the music of Lili Boulanger culminates with her final completed composition, D’un matin de printemps (“Of a spring morning”), a bright and impressionistic work for orchestra that owes much of its musical language to Claude Debussy. This is followed by Johannes Brahms’ Op. 17 collection of four songs scored for the unusual combination of women’s choir, two horns, and harp. The first half of the concert concludes with Bach’s sunny Easter cantata Der Himmel Lacht! (“The sky is laughing!”), a festive work for soloists, choir, and orchestra. The grand finale is Robert Schumann’s “Spring” Symphony, which the composer said “was written in that rush of spring which carries a man away even in his old age, and comes over him anew every year.” Full of sparkle and verve (and sketched out in a mere four days!), it brims with spontaneity.