The professional chamber choir that bills itself as The Crossing is dedicated exclusively to new music. Donald Nally, the ensemble’s conductor, has commissioned north of 200 works, often involving collaborations with other adventuresome institutions. Recognition of The Crossing’s excellence and enterprise has come in the form of 10 Grammy nominations, nine wins, and Musical America’s prize for best ensemble of 2024. The description of The Crossing’s latest program mentions “joyful motets and sorrowful laments, asking the question, ‘What is nativity?’” and answering mysteriously, “Mother. Birth. Gloria. Snow. Air Raid.” Featured works include a choral transcription of the Ukrainian composer Natalia Tsupryk’s Kyiv and Nativity by Sarah Rimkus, featuring the cellist Thomas Mesa. —Matthew Gurewitsch