For its 10th Stephen Sondheim musical, the Lyric Stage Company of Boston is producing one of his most challenging and rarely performed, “Pacific Overtures.” Based on a pivotal time in Japanese-American relations in the 1850s, it explores the complexities when East meets West in a tale of domination, turmoil, murder and comeuppance with Sondheim’s signature wit and creativity.The starting point of “Pacific Overtures,” which runs May 10 to June 16, is [...]