I need more than two hands to count the number of operas I’ve attended in Boston so far this year. Two productions by the Boston Lyric Opera, our leading company; nine (four fully staged) by our newest company, Odyssey Opera; a brilliant concert version by the BSO of Szymanowski’s disturbing and mesmerizing King Roger; all three of Monteverdi’s surviving operas presented by the Boston Early Music Festival, performed in repertory for possibly the very first time; a rarely produced Mozart masterpiece, Die Entführung aus dem Serail, in a solid and often eloquently sung concert version by Emmanuel Music; the world premiere of Crossing, 25-year-old Matthew Aucoin’s one-act opera about Whitman in the Civil War, presented by A.R.T.; and the first local production of Hulak-Artemovsky’s Cossack Beyond the Danube, the Ukrainian national opera, by Commonwealth Lyric Theatre (imaginatively staged and magnificently sung). Not to mention several smaller production I couldn’t actually get to—including an adventurous new work, Per Bloland’s Pedr Solis, by the heroic Guerrilla Opera, which I got to watch only on-line, and Boston Opera Collaborative’s Ned Rorem Our Town (music I’m not crazy about, but friends I trust liked the production). A lot of opera! But how full is the cup?