With his first new album in four years, Mercy, the harpist and classically trained choral singer born Pat Grossi, continues to create euphoric electronic music. 9 p.m. Great American Music Hall. www.gamh.com. “Cymbeline”: Marin Shakespeare Company opens its 2015 summer season with one of Shakespeare’s more rarely seen late romances, a tale of ancient Britain with an unusually grisly rude awakening.