San Francisco-based Philharmonia Baroque Orchestra has announced its exciting 2022-23 season spotlighting rare works by Handel and featuring Anthony Roth Costanzo, along with 13 guest artist debuts. Here’s what’s in store for Bay Area audiences. For this article, only vocal performances are listed. First up is Händel’s oratorio “Theodora,” featuring mezzo-soprano Helen Charlston in her PBO and American debut, soprano {…}