At face value, the idea of pairing music of Beethoven and great American maverick Charles Ives — the basis of tonight’s edition of the current Camerata Pacifica season, at Hahn Hall — might seem a study in sharp contrasts. Yet while there are radical differences between the respective musical languages of Beethoven’s Opus 127 string quartet and Mr. Ives’ challenging and rewarding “Concord Sonata,” they share a common drive for innovation and breaking into new expressive ground and plumbing emotional depths. The respected Calder Quartet gives us the former, pianist Molly Morkorski the latter, in what promises to be one of the stronger evenings of the group’s concert season. Camerata Pacifica is presently in the midst of a two-season long programming arc celebrating Beethoven in sync with his 250th birthday in 2020, a project combining concerts and panel discussions, and dubbed “Why Beethoven?” Answers are being delivered, concert by concert. Tonight at 7:30 p.m., Hahn Hall, Music Academy of the West, 1070 Fairway Road. Tickets are $50 to $56. Information: 805-884-8410, 800-557-BACH (2224), www.cameratapacifica.org.