Period-instrument Philip Glass? Who’d have thought. If Handel was the rock-star opera composer of the mid-18th century, then there’s a strong case to be made for Glass as his equivalent 250 years later. Pairing these two composers on the same album is not only an intriguing idea, but it’s also a very successful one. Costanzo’s rich countertenor voice wraps itself effortlessly around Handel’s mellifluous lines just as it rides Glass’ driving rhythms with ease. He has performed Glass’ Akhnaten on stage and sings the role with a real sense of the character’s predicament; his way with Handel is equally convincing.