Manchester Choral Society will join forces with the Seacoast-based ensemble Portsmouth Pro Musica for a major choral-orchestral project featuring Franz Schubert’s Mass in E-flat and Felix Mendelssohn’s Psalm 42. Performances will bring together more than 90 singers, with professional soloists, and a full orchestra. Manchester Choral Society Music Director Dan Perkins and Portsmouth Pro Musica Music Director Priscilla French will share the podium for this collaborative effort, uniting two respected New Hampshire choral organizations in a dynamic musical partnership.