Philip Glass’ 2014 opera, his 26th, is a tightly scored ensemble piece for just eight singers. But these modest forces give an intensity to Kafka’s nightmarish world of oppression and injustice. The ultimately tragic tale of K., accused of an unspecified crime on his 30th birthday, is told by Glass with pared-down, menacing music—all helped along by an expertly adapted, spare libretto by playwright Christopher Hampton. The listening experience is immersive, with Music Theatre Wales’ singers enunciating words with crystal clarity, and its orchestra providing rock-solid support.