The 2023–24 season of the Curtis Opera Theatre kicks off on Nov. 10 and 12 with George Frideric Handel’s “L’Allegro, il Penseroso ed il Moderato” at the Philadelphia Film Center. This piece was inspired by John Milton’s “Paradise Lost” and adapted by Charles Jennens. Chas Rader-Shieber directs, and Nicholas McGegan conducts. The opera comprises a cast of rising vocalists backed {…}