Chamber opera is by any metric a niche genre, but it’s proving a winning proposition for Laura Kaminsky, ranked by The Washington Post among today’s 35 top classical composers. Her sensitive, hypnotic As One (2014, libretto by Mark Campbell and Kimberly Read) addresses the coming of age of the transgender woman Hannah, who appears in a baritone “Before” and a mezzo-soprano “After” avatar. Affordably scored for just two voices and a string quartet, As One is showing legs in an ever-more-gender-fluid environment. This time out, Kaminsky turns her attention to an aging singer and composer named Lili as she crosses the threshold of dementia. The role is sure to resonate with the soprano Lucy Shelton, who is herself a composer and for decades an engaged champion of living composers. Blythe Gaissert appears as Dr. Claire Klugman, who researches the effects of music on memory. Cristina María Castro sings Sunny, a clarinetist whose life becomes entwined with Lili’s; Yasmina Spiegelberg plays Sunny’s pivotal instrumentals. Kaminsky’s librettist on Lucidity is David Cote, known to stagestruck New Yorkers as the long-serving theater editor and chief drama critic of Time Out. —Matthew Gurewitsch