This season, the Boston Classical Orchestra and music director Steven Lipsitt are celebrating bicentennials of Felix Mendelssohn (b. 1809) and Robert Schumann (b. 1810), but last weekend, they first needed to mark another birthday: their own. For its 30th anniversary, the group commissioned Cambridge composer Howard Frazin’s “In the Forests of the Night,’’ an atmospheric overture that had its premiere on Saturday with a repeat performance on Sunday.
Frazin’s starting point was his own setting of William Blake’s “The Tyger’’ (given a rhapsodic reading by mezzo-soprano Krista Rivers and pianist Linda Osborn-Blaschke at a pre-concert talk), expanded into an arching string of nocturnes, foreboding to frightening to gently mysterious: rustling strings, keening fragments of melody. Harmonies are tonal, but used more as a coloristic resource than a structural scaffold. Compared to song and poem, the overture’s climax is shifted toward the center; the symmetry was less fearful, but provided a more wide-ranging journey. Lipsitt and the orchestra gave the piece a rich debut.