There are few sure things in the music world, but one notable exception has been the critically lauded Handel opera and oratorio performances by The English Concert conducted by Harry Bicket. This season they perform the sparkling oratorio Semele, a tale of a princess’s love affair with a god and her quest for immortality told in a stream of easy-flowing melodies and dazzling coloratura. Show-stopping arias include the title character’s florid “Endless pleasure, endless love” and touching “O sleep, why dost thou leave me,” and Jupiter’s “Where’er you walk”—a recital favorite to this day.